Compositions for dyeing keratin fibers, containing cationic indolizine derivatives, and dyeing process

ABSTRACT

Compositions for the oxidation dyeing of keratin fibres, containing at least one oxidation base and at least one coupler chosen from indolizine derivative comprising at least one cationic group Z, Z being chosen from quaternized aliphatic chains, aliphatic chains comprising at least one quaternized saturated ring, and aliphatic chains comprising at least one quaternized unsaturated ring. Methods of using these cationic indolizine derivatives as couplers for the oxidation dyeing of keratin fibres, in combination with at least one oxidation base, and to dyeing processes using them. Some of these cationic indolizine derivatives are novel.

[0001] The invention relates to compositions for the oxidation dyeing ofkeratin fibres, comprising at least one oxidation base and at least onecoupler chosen from indolizine derivatives comprising at least onecationic group Z, wherein Z may be chosen from quaternized aliphaticchains, aliphatic chains comprising at least one quaternized saturatedring, and aliphatic chains comprising at least one quaternizedunsaturated ring, to oxidation dyeing processes using them and to novelcationic indolizine derivatives.

[0002] Dye compositions comprising oxidation dye precursors are known inthe art for dyeing keratinous fibres, such as human hair. The oxidationdye precursors include ortho-phenylenediamines, para-phenylenediamines,ortho-aminophenols, para-aminophenols, and heterocyclic compounds. Theseare generally known as oxidation bases. The oxidation dye precursors,i.e., oxidation bases, are generally colorless or weakly coloredcompounds which may give rise to colored compounds and dyes whencombined with oxidizing products via oxidative coupling.

[0003] The shades obtained with these oxidation bases may be varied bycombining them with couplers or coloration modifiers. Such colorationmodifiers may, for example, be chosen from aromatic meta-diamines,meta-aminophenols, meta-diphenols, and certain heterocyclic compounds,such as indole compounds.

[0004] The variety of molecules used as oxidation bases and couplers maymake it possible to obtain a wide range of colours.

[0005] The so-called “permanent” coloration obtained from using theseoxidation dyes should have at least one of the following desirablecharacteristics. The coloration should have no toxicological drawbacks,the shades obtained should have the desired intensity, and thecoloration should have good resistance to external agents to which thefibres may be subjected, such as light, bad weather, washing,permanent-waving, perspiration, and rubbing. The dyes should allowcoverage of white hairs, and should be as unselective as possible, thatis, they should allow only the smallest possible differences incoloration along the same keratin fiber, which may be differentlysensitized (i.e. damaged) between its end tip and its root.

[0006] Indazole-type compounds have been used in the field of hairdyeing. For example, in DE-A-1 492 166, the disclosure of which isincorporated herein by reference, the polycondensation of such compoundsvia oxidation has been proposed; in DE-A-2 623 564, the disclosure ofwhich is incorporated herein by reference, it has been proposed tocombine hydroxy-indazoles with tetraaminopyrimidines, and in U.S. Pat.No. 4,013,404, the disclosure of which is incorporated herein byreference, certain aminoindazoles and their use as oxidation dyeprecursors have been proposed.

[0007] The inventors have discovered, entirely surprisingly andunexpectedly, that the indolizine derivatives of formula (I) definedbelow comprising at least one cationic group Z, Z being chosen fromquaternized aliphatic chains, aliphatic chains comprising at least onequaternized saturated ring and aliphatic chains comprising at least onequaternized unsaturated ring, are not only suitable for use as couplersfor oxidation dyeing, but also make it possible to obtain dyecompositions which provide at least one of intense colorations in a verywide range of shades and excellent properties of resistance to thevarious treatments to which the keratin fibres may be subjected.

[0008] A subject of the invention is thus a composition for dyeingkeratin fibres, such as, for example, human keratin fibres such as thehair, wherein the composition comprises, in a medium which is suitablefor dyeing:

[0009] (i) at least one oxidation base; and

[0010] (ii)at least one coupler chosen from indolizine derivatives offormula (I) and the acid addition salts thereof:

[0011] in which:

[0012] n may be an integer from 0 to 4;

[0013] R₁ and R₃, which may be identical or different, are each chosenfrom hydrogen atoms; halogen atoms; Z groups; C₁-C₄ alkyl radicals;C₁-C₄ alkoxy radicals; C₁-C₄ monohydroxyalkyl radicals; C₂-C₄polyhydroxyalkyl radicals; C₁-C₄ aminoalkyl radicals; acetylaminoradicals; acetylamino-(C₁-C₄)alkyl radicals; (C₁-C₄)alkoxy(C₁-C₄)alkylradicals; mono(C₁-C₄)alkylamino(C₁-C₄)alkyl radicals;di(C₁-C₄)alkylamino(C₁-C₄)alkyl radicals; aminocarboxy(C₁-C₄)alkylradicals; acetyl(C₁-C₄)alkylamino(C₁-C₄)alkyl radicals; and aromaticrings which are optionally substituted with at least one radical chosenfrom halogen atoms, C₁-C₄ alkyl radicals, trifluoro-methyl radicals,C₁-C₄ alkoxy radicals, amino radicals, mono- and disubstituted aminoradicals wherein the substituent is chosen from C₁-C₄ alkyl radicals,(C₁-C₄)alkylamino(C₁-C₄)alkyl radicals, di(C₁-C₄)alkylamino(C₁-C₄)alkylradicals, carboxyl radicals and sulphoxy radicals;

[0014] R₃ may optionally further be chosen from 5- and 6-memberedunsaturated heterocycles;

[0015] R₂ and R₄, which may be identical or different, are each chosenfrom hydrogen atoms; halogen atoms, Z groups; C₁-C₄ alkyl radicals,C₁-C₄ monohydroxyalkyl radicals, C₂-C₄ polyhydroxyalkyl radicals, C₁-C₄aminoalkyl radicals, mono(C₁-C₄)-alkylamino(C₁-C₄)alkyl radicals,di(C₁-C₄)alkyl-amino(C₁-C₄)alkyl radicals, carboxyl radicals, cyanoradicals, carboxy(C₁-C₄)alkyl radicals, nitro radicals and 5- and6-membered aromatic rings which are optionally substituted with at leastone radical chosen from halogen atoms, C₁-C₄ alkyl radicals,trifluoromethyl radicals, C₁-C₄ alkoxy radicals, amino radicals andmono- and disubstituted amino radicals wherein the substituent is chosenfrom C₁-C₄ alkyl radicals, (C₁-C₄)alkylamino-(C₁-C₄)alkyl radicals,di(C₁-C₄)alkylamino-(C₁-C₄)alkyl radicals, carboxyl radicals andsulphoxy radicals;

[0016] Z is chosen from the following unsaturated cationic groups offormulae (II) and (III) below, and the saturated cationic groups offormula (IV) below:

[0017] in which:

[0018] D is a linker arm which is chosen from linear and branchedalkylene chains, preferably containing from 1 to 14 carbon atoms, whichmay be interrupted by at least one hetero atom, and which may besubstituted with at least one substituent chosen from hydroxyl and C₁-C₆alkoxy radicals, and which may bear at least one ketone function;

[0019] the ring members E, G, J, L and M, which may be identical ordifferent, are chosen from carbon, oxygen, sulphur and nitrogen atoms;

[0020] b is an integer from 0 to 4;

[0021] m is an integer from 0 to 5;

[0022] the radicals R, which may be identical or different, are chosenfrom a second group Z, which may be identical to or different from thefirst group Z, halogen atoms, hydroxyl radicals, C₁-C₆ alkyl radicals,C₁-C₆ monohydroxyalkyl radicals, C₂-C₆ polyhydroxyalkyl radicals, nitroradicals, cyano radicals, cyano(C₁-C₆)alkyl radicals, C₁-C₆ alkoxyradicals, tri(C₁-C₆)alkylsilane(C₁-C₆)alkyl radicals, amido radicals,aldehydo radicals, carboxyl radicals, (C₁-C₆)alkylcarbonyl radicals,thio radicals, C₁-C₆ thioalkyl radicals, C₁-C₆ alkylthio radicals, aminoradicals, amino radicals protected with at least one group chosen from(C₁-C₆)alkylcarbonyls, carbamyls and C₁-C₆ alkylsulphonyl radicals; NHR″and NR′R″ groups in which R″ and R′″, which may be identical ordifferent, are chosen from C₁-C₆ alkyl radicals, C₁-C₆ monohydroxyalkylradicals and C₂-C₆ polyhydroxyalkyl radicals;

[0023] R₅ is chosen from C₁-C₆ alkyl radicals, C₁-C₆ mono-hydroxyalkylradicals, C₂-C₆ polyhyd roxyalkyl radicals, cyano(C₁-C₆)alkyl radicals,tri(C₁-C₆)-alkylsilane(C₁-C₆)alkyl radicals, (C₁-C₆)alkoxy-(C₁-C₆)alkylradicals, carbamyl(C₁-C₆)alkyl radicals, (C₁-C₆)alkylcarboxy(C₁-C₆)alkylradicals, benzyl radicals and second Z groups which may be identical toor different from the first Z groups;

[0024] R₆, R₇ and R₈, which may be identical or different, are eachchosen from C₁-C₆ alkyl radicals, C₁-C₆ monohydroxyalkyl radicals, C₂-C₆polyhydroxyalkyl radicals, (C₁-C₆)alkoxy(C₁-C₆)alkyl radicals,cyano(C₁-C₆)alkyl radicals, aryl radicals, benzyl radicals,amido(C₁-C₆)alkyl radicals, tri(C₁-C₆)alkylsilane(C₁-C₆)alkyl radicalsand C₁-C₆ aminoalkyl radicals in which the amine is protected with atleast one group chosen from (C₁-C₆)alkylcarbonyls, carbamyls and C₁-C₆alkylsulphonyl radicals; two of the radicals R₆, R₇ and R₈, may alsoform, together with the nitrogen atom to which they are attached, 5- and6-membered saturated carbon-based rings and rings containing at leastone hetero atom, such as, for example, a pyrrolidine ring, a piperidinering, a piperazine ring or a morpholine ring, it being possible for thesaid ring to be optionally substituted with at least one substituentchosen from halogen atoms, hydroxyl radicals, C₁-C₆ alkyl radicals,C₁-C₆ monohydroxyalkyl radicals, C₂-C₆ polyhydroxyalkyl radicals, nitroradicals, cyano radicals, cyano(C₁-C₆)alkyl radicals, C₁-C₆ alkoxyradicals, tri(C₁-C₆)alkylsilane(C₁-C₆)alkyl radicals, amido radicals,aldehydo radicals, carboxyl radicals, keto(C₁-C₆)alkyl radicals, thioradicals, C₁-C₆ thioalkyl radicals, C₁-C₆ alkylthio radicals, aminoradicals and amino radical protected with at least one group chosen from(C₁-C₆)alkylcarbonyls, carbamyls and C₁-C₆ alkylsulphonyl radicals;

[0025] one of the radicals R₆, R₇ and R₈ may optionally be chosen fromsecond Z groups, which may be identical to or different from the first Zgroups;

[0026] R₉ is chosen from C₁-C₆ alkyl radicals; C₁-C₆ monohydroxyalkylradicals; C₂-C₆ polyhydroxyalkyl radicals; aryl radicals; benzylradicals; C₁-C₆ aminoalkyl radicals, C₁-C₆ aminoalkyl radicals whereinthe amine is protected by at least one group chosen from(C₁-C₆)alkylcarbonyls, carbamyls and C₁-C₆ alkylsulphonyl radicals;carboxy(C₁-C₆)alkyl radicals; cyano(C₁-C₆)alkyl radicals;carbamyl(C₁-C₆)alkyl radicals; C₁-C₆ trifluoroalkyl radicals;tri(C₁-C₆)alkylsilane(C₁-C₆)alkyl radicals; sulphonamido(C₁-C₆)alkylradicals; (C₁-C₆)alkylcarboxy(C₁-C₆)alkyl radicals;(C₁-C₆)alkylsulphinyl(C₁-C₆)alkyl radicals;(C₁-C₆)alkylsulphonyl(C₁-C₆)alkyl radicals; (C₁-C₆)alkylketo(C₁-C₆)alkylradicals; N-(C₁-C₆)alkylcarbamyl(C₁-C₆)alkyl radicals; andN-(C₁-C₆)alkylsulphonamido(C₁-C₆)alkyl radicals;

[0027] a and y are integers equal to 0 or 1; with the followingprovisos:

[0028] in the unsaturated cationic groups of formula (II):

[0029] when a=0, the linker arm D is attached to the nitrogen atom,

[0030] when a=1, the linker arm D is attached to one of the ring membersE, G, J and L,

[0031] y cannot take the value 1 except:

[0032] 1) when the ring members E, G, J and L simultaneously represent acarbon atom, and when the radical R₅ is attached to the nitrogen atom ofthe unsaturated ring; or alternatively

[0033] 2) when at least one of the ring members E, G, J and L representsa nitrogen atom to which the radical R₅ is attached;

[0034] when b is at least 2, two adjacent radicals R may also formtogether a ring chosen from unsaturated 5- and 6-membered carbon-basedrings and rings containing at least one hetero atom;

[0035] in the unsaturated cationic groups of formula (III):

[0036] when a=0, the linker arm D is attached to the nitrogen atom,

[0037] when a=1, the linker arm D is attached to one of the ring membersE, G, J, L and M,

[0038] y cannot take the value 1 except when at least one of the ringmembers E, G, J, L and M represents a divalent atom, and when theradical R₅ is attached to the nitrogen atom of the unsaturated ring;

[0039] when m is at least 2, two adjacent radicals R may also formtogether unsaturated 5- and 6-membered carbon-based rings and ringscontaining at least one hetero atom;

[0040] in the cationic groups of formula (IV):

[0041] when a=0, the linker arm D is attached to the nitrogen atombearing the radicals R₆ to R₈,

[0042] when a=1, two of the radicals R₆ to R₈ form, together with thenitrogen atom to which they are attached, saturated 5- and 6-memberedrings as defined above, and the linker arm D is attached to a carbonatom of the said saturated ring;

[0043] X⁻ is chosen from monovalent and divalent anions and may bechosen, for example, from halides such as chloride, bromide, fluorideand iodide, hydroxides, hydrogen sulphates and C₁-C₆ alkyl sulphatessuch as, for example, methyl sulphates and ethyl sulphates;

[0044] it being understood that:

[0045] at least one of the radicals R₁ and R₃ represents a hydrogenatom; and

[0046] the number of cationic groups Z is at least equal to 1.

[0047] Colorations obtained using the inventive dye compositions maypossess at least one of the following desirable characteristics:unselectivity, powerful, enable a variety of shades, and excellentproperties of resistance to at least one of atmospheric agents chosenfrom light and bad weather, perspiration and treatments to which thehair may be subjected (such as shampooing, permanent-waving, etc.).

[0048] As used herein, “at least one” means one or more and thusincludes individual components as well as mixtures/combinations.Further, as used herein, unless otherwise noted, alkyl radicals may bechosen from substituted, unsubstituted, linear, branched, and cyclicalkyl radicals. Similarly, as used herein and unless otherwise noted,the alkyl radicals of alkoxy radicals may be chosen from substituted,unsubstituted, linear, branched, and cyclic alkyl radicals.

[0049] Non-limiting examples of aromatic rings of formula (I) includephenyl rings, nitrophenyl rings, alkylphenyl rings, alkoxyphenyl rings,polyalkyl-phenylrings and polyalkoxyphenyl rings.

[0050] Non-limiting examples of unsaturated 5- and 6-memberedheterocycles, such as may be represented by R₃, include pyrrole rings,pyridine rings, pyrimidine rings, imidazole rings, pyrazole rings,oxazole rings, thiazole rings, triazole rings, pyrazolotriazole rings,pyrazoloimidazole rings, pyrrolotriazole rings, pyrazolopyrimidinerings, pyrazolopyridine rings, benzimidazole rings, benzoxazole rings,benzothiazole rings, indole rings, indoline rings, indolidine rings,isoindolidine rings, benzotriazoline rings, pyrazine rings, oxazinerings, triazine rings, quinoline rings, tetrahydro-quinoline rings,benzimidazolidine rings and benzopyrimidine rings.

[0051] Non-limiting examples of unsaturated group Z rings of formula(II) include pyrrole rings, imidazole rings, pyrazole rings, oxazolerings, thiazole rings, triazole rings, pyrazoltri-azolinium rings,pyrazoloimidazolinium rings, pyrrolotriazolinium rings,pyrazolopyrimidinium rings, pyrazolopyridinium rings, benzimidazoliniumrings, benzoxazolinium rings, benzothiazolinium rings, indolinium rings,indolidinium rings, isoindolinium rings, indazolinium rings andbenzotriazolinium rings.

[0052] Non-limiting examples of unsaturated group Z rings of formula(III) include pyridine rings, pyrimidine rings, pyrazine rings, oxazinerings, triazine rings, quinolinium rings and tetrahydroquinoliniumrings.

[0053] Non-limiting examples of the compounds of formula (I) include:

[0054] N,N-dimethyl-2-phenyl-N-(phenylmethyl)-1-indolizinepropanaminium;

[0055] N,N,N-trimethyl-2-phenyl-1-indolizinethanaminium

[0056] N,N,N-trimethyl-2-phenyl-1-indolizinepropanaminium bromide;

[0057] 4-methyl-4-[2-(2-phenyl-1-indolizinyl)ethyl]morpholinium bromide;

[0058] N,N-dimethyl-2-phenyl-N-(phenylmethyl)-1-indolizinepropanaminiumnitrate;

[0059] N,N-dimethyl-2-phenyl-N-(phenylmethyl)-1-indolizinepropanaminiumchloride;

[0060] N,N,N-trimethyl-2-phenyl-1-indolizinethanaminium methyl sulphate;

[0061] trimethyl[2-(2-phenyl-1-indolizinyl)ethyl]ammonium iodide;

[0062] trimethyl[2-(2-phenyl-1-indolizinyl)ethyl]ammonium bromide;

[0063] 1-methyl-2-[2-(7-methyl-2-phenylindolizin-3-yl)ethyl]pyridiniummethyl sulphate;

[0064]3-methyl-1-[2-(7-methyl-2-phenylindolizin-3-yl)-2-oxoethyl]-3H-imidazol-1-iumchloride;

[0065]3-methyl-1-[2-(2-methylindolizin-3-yl)-2-oxoethyl]-3H-imidazol-1-iumchloride;

[0066]1-{2-[2-(4-methoxyphenyl)-8-methylindolizin-3-yl]-2-oxoethyl}-3-methyl-3H-imidazol-1-iumchloride;

[0067]3-methyl-1-{2-[8-methyl-2-(3-nitrophenyl)indolizin-3-yl]-2-oxoethyl}-3H-imidazol-1-iumchloride;

[0068] 1-{2-[2-(3-nitrophenyl)indolizin-3-yl]-2-oxoethyl}pyridiniumchloride;

[0069] 1-[2-oxo-2-(2-phenylindolizin-3-yl)ethyl]pyridinium chloride;

[0070] 1-[2-oxo-2-(2-m-tolylindolizin-3-yl)ethyl]pyridinium chloride;

[0071]1-[2-(8,1-{2-[2-(4-methoxyphenyl)-8-methylindolizin-3-yl]-2-oxoethyl}-2-methylpyridiniumchloride;

[0072] 2-phenylindolizin-3-yl)-2-oxoethyl]pyridinium methyl chloride;

[0073] [2-(8-methyl-2-phenylindolizin-3-yl)-2-oxoethyl] pyridiniumchloride;

[0074]2-methyl-1-{2-[2-(3-nitrophenyl)indolizin-3-yl]-2-oxoethyl}pyridiniumchloride;

[0075] 2-methyl-1-[2-oxo-2-(2-phenylindolizin-3-yl)ethyl]pyridiniumchloride;

[0076]2-methyl-1-{2-[8-methyl-2-(3-nitrophenyl)indolizin-3-yl]-2-oxoethyl}pyridiniumchloride;

[0077] 2-methyl-1-[2-(8-methyl-2-phenylindolizin-3-yl)-2-oxoethyl]pyridinium chloride;

[0078]3-methoxycarbonyl-1-{2-[2-(3-nitrophenyl)indolizin-3-yl]-2-oxoethyl}pyridiniumchloride;

[0079] 3-methoxycarbonyl-1-[2-oxo-2-(2-phenylindolizin-3-yl)ethyl]pyridinium chloride;

[0080]3-methoxycarbonyl-1-{2-[2-(4-methoxyphenyl)-8-methylindolizin-3-yl]-2-oxoethyl}pyridiniumchloride;

[0081]3-methoxycarbonyl-1-(2-[8-methyl-2-(3-nitrophenyl)indolizin-3-yl]-2-oxoethyl}pyridiniumchloride;

[0082]3-methoxycarbonyl-1-[2-(8-methyl-2-phenylindolizin-3-yl)-2-oxoethyl]pyridinium chloride; and the acid addition salts thereof.

[0083] According to the present invention, the at least one coupler maybe present in the composition in an amount generally ranging from0.0005% to 12% by weight relative to the total weight of the dyecomposition, such as from 0.005% to 6% by weight.

[0084] The nature of the at least one oxidation base used in the presentinvention may not be critical. In one embodiment, the at least oneoxidation base is chosen from para-phenylenediamines, double bases,para-aminophenols, ortho-aminophenols, heterocyclic oxidation bases, andthe acid addition salts of any of the foregoing.

[0085] Non-limiting examples of para-phenylenediamines which can be usedas the at least one oxidation base include compounds of formula (V) andthe acid addition salts thereof:

[0086] wherein:

[0087] R₁₀ is chosen from a hydrogen atom, C₁-C₄ alkyl radicals, C₁-C₄monohydroxyalkyl radicals, C₂-C₄ polyhydroxyalkyl radicals,(C₁-C₄)alkoxy(C₁-C₄)alkyl radicals, C₁-C₄ alkyl radicals substitutedwith at least one radical chosen from nitrogen-containing radicals,phenyl radicals and 4′-aminophenyl radicals;

[0088] R₁₁ is chosen from a hydrogen atom, C₁-C₄ alkyl radicals, C₁-C₄monohydroxyalkyl radicals, C₂-C₄ polyhydroxyalkyl radicals,(C₁-C₄)alkoxy(C₁-C₄)alkyl radicals and C₁-C₄ alkyl radicals substitutedwith at least one nitrogen-containing radical;

[0089] R₁₂ is chosen from a hydrogen atom, halogen atoms such as achlorine atom, a bromine atom, an iodine atom and a fluorine atom, C₁-C₄alkyl radicals, C₁-C₄ monohydroxyalkyl radicals, C₁-C₄ hydroxyalkoxyradicals, acetylamino(C₁-C₄)alkoxy radicals, mesylamino-(C₁-C₄)alkoxyradicals and carbamoylamino(C₁-C₄)alkoxy radicals;

[0090] R₁₃ is chosen from a hydrogen atom, halogen atoms and C₁-C₄ alkylradicals.

[0091] Non-limiting examples of nitrogen containing radicals of formula(V) above include amino radicals, mono(C₁-C₄)alkylamino radicals,di(C₁-C₄)alkylamino radicals, tri(C₁-C₄)alkylamino radicals,monohydroxy(C₁-C₄)alkylamino radicals, imidazolinium radicals andammonium radicals.

[0092] Non-limiting examples of the para-phenylenediamines of formula(V) above include para-phenylenediamine, para-tolylenediamine,2-chloro-para-phenylenediamine, 2,3-dimethyl-para-phenylenediamine,2,6-dimethyl-para-phenylenediamine, 2,6-diethyl-para-phenylenediamine,2,5-dimethyl-para-phenylenediamine, N,N-dimethyl-para-phenylenediamine,N,N-diethyl-para-phenylenediamine, N,N-dipropyl-para-phenylened iamine,4-amino-N,N-diethyl-3-methylaniline,N,N-bis(-hydroxyethyl)-para-phenylenediamine,4-N,N-bis(-hydroxyethyl)amino-2-methylaniline,4-N,N-bis(-hydroxyethyl)amino-2-chloroaniline,2-hydroxyethyl-para-phenylenediamine, 2-fluoro-para-phenylenediamine,2-isopropyl-para-phenylenediamine,N-(-hydroxypropyl)-para-phenylenediamine,2-hydroxymethyl-para-phenylenediamine,N,N-dimethyl-3-methyl-para-phenylenediamine,N-ethyl-N-(-hydroxyethyl)-para-phenylenediamine,N-(,-dihydroxy-propyl)-para-phenylenediamine,N-(4′-aminophenyl)-para-phenylenediamine,N-phenyl-para-phenylenediamine, 2-hydroxyethyloxy-para-phenylenediamine,2-acetylamino-ethyloxy-para-phenylenediamine andN-(-methoxyethyl)-para-phenylenediamine, and acid addition salts of anyof the foregoing.

[0093] In one embodiment, para-phenylenediamines of formula (V) aboveare chosen from para-phenylenediamine, para-tolylenediamine,2-isopropyl-para-phenylenediamine, 2-hydroxyethyl-para-phenylenediamine,2-hydroxyethyloxy-para-phenylenediamine,2,6-dimethyl-para-phenylenediamine, 2,6-diethyl-para-phenylenediamine,2,3-dimethyl-para-phenylenediamine,N,N-bis(-hydroxyethyl)-para-phenylenediamine,2-chloro-para-phenylenediamine and2-acetylaminoethyloxy-para-phenylenediamine, and the acid addition saltsof any of the foregoing.

[0094] As used herein, “double bases” means compounds comprising atleast two aromatic entities substituted with at least one radical chosenfrom amino radicals and hydroxyl radicals.

[0095] Non-limiting examples of double bases which may be used as the atleast one oxidation base according to the present invention includecompounds of formula (VI) and the acid addition salts thereof:

[0096] in which:

[0097] B₁ and B₂, which may be identical or different, are each chosenfrom hydroxyl radicals and —NH₂ radicals, optionally substituted with atleast one radical chosen from C₁-C₄ alkyl radicals and linker arms Y;

[0098] linker arm Y is chosen from linear and branched divalent alkylenechains comprising from 1 to 14 carbon atoms, wherein said divalentalkylene chains may optionally be interrupted by at least onenitrogen-containing radical and optionally interrupted by at least onehetero atom such as an oxygen atom, a sulphur atom or a nitrogen atom,further wherein said divalent alkylene chains may optionally beterminated with at least one nitrogen-containing radical and optionallyinterrupted by at least one heteroatom such as an oxygen atom, a sulphuratom or a nitrogen atom, and further wherein said divalent alkylenechains may optionally be substituted with at least one radical chosenfrom hydroxyl radicals and C₁-C₆ alkoxy radicals;

[0099] R₁₄ and R₁₅, which may be identical or different, are each chosenfrom a hydrogen atom, halogen atoms, C₁-C₄ alkyl radicals, C₁-C₄monohydroxyalkyl radicals, C₂-C₄ polyhydroxyalkyl radicals, C₁-C₄aminoalkyl radicals and linker arms Y;

[0100] R₁₆, R₁₇, R₁₈, R₁₉, R₂₀ and R₂₁, which may be identical ordifferent, are each chosen from a hydrogen atom, linker arms Y and C₁-C₄alkyl radicals;

[0101] with the proviso that only one linker arm Y is present in eachcompound of formula (III).

[0102] Non-limiting examples of double bases of formula (VI)includeN,N′-bis(β-hydroxyethyl)-N,N′-bis(4′-aminophenyl)-1,3-diaminopropanol,N,N′-bis(β-hydroxyethyl)-N,N′-bis(4′-aminophenyl)ethylenediamine,N,N′-bis(4-aminophenyl)tetramethylenediamine,N,N′-bis(β-hydroxyethyl)-N,N′-bis(4-aminophenyl)tetramethylenediamine,N,N′-bis(4-methylaminophenyl)tetramethylenediamine,N,N′-bis(ethyl)-N,N′-bis(4′-amino-3′-methyl-phenyl)ethylenediamine,1,8-bis(2,5-diaminophenoxy)-3,5-dioxaoctane, and the acid addition saltsof any of the foregoing.

[0103] In one embodiment, double bases of formula (VI)are chosen fromN,N′-bis(β-hydroxyethyl)-N,N′-bis(4′-aminophenyl)-1,3-diaminopropanol,1,8-bis(2,5-diaminophenoxy)-3,5-dioxaoctane and the acid addition saltsof any of the foregoing.

[0104] Non-limiting examples of para-aminophenols which may be usedaccording to the present invention include compounds of formula (VII)and the acid addition salts thereof:

[0105] wherein:

[0106] R₂₂ is chosen from a hydrogen atom, halogen atoms, C₁-C₄ alkylradicals, C₁-C₄ monohydroxyalkyl radicals, (C₁-C₄)alkoxy(C₁-C₄)alkylradicals, C₁-C₄ aminoalkyl radicals andhydroxy(C₁-C₄)alkylamino(C₁-C₄)alkyl radicals; and

[0107] R₂₃ is chosen from a hydrogen atom, halogen atoms, C₁-C₄ alkylradicals, C₁-C₄ monohydroxyalkyl radicals, C₂-C₄ polyhydroxyalkylradicals, C₁-C₄ aminoalkyl radicals, cyano(C₁-C₄)alkyl radicals and(C₁-C₄)alkoxy(C₁-C₄)alkyl radicals,

[0108] with the proviso that at least one of R₂₂ and R₂₃ is a hydrogenatom.

[0109] Non-limiting examples of para-aminophenols of formula (VII)include para-aminophenol, 4-amino-3-methylphenol,4-amino-3-fluorophenol, 4-amino-3-hydroxymethylphenol,4-amino-2-methylphenol, 4-amino-2-hydroxymethylphenol,4-amino-2-methoxymethylphenol, 4-amino-2-aminomethylphenol,4-amino-2-(β-hydroxyethylaminomethyl)phenol, 4-amino-2-fluorophenol andthe acid addition salts of any of the foregoing.

[0110] Non-limiting examples of ortho-aminophenols which may be used asthe at least one oxidation base include 2-aminophenol,2-amino-5-methylphenol, 2-amino-6-methylphenol,5-acetamido-2-aminophenol and the acid addition salts of any of theforegoing.

[0111] Non-limiting examples of heterocyclic bases which may be used asthe at least one oxidation base include pyridine derivatives, pyrimidinederivatives, pyrazole derivatives and the acid addition salts of any ofthe foregoing.

[0112] Non-limiting examples of pyridine derivatives include compoundsdisclosed, for example, in British Patents GB 1 026 978 and GB 1 153196, the disclosures of which are incorporated herein by reference, suchas 2,5-diaminopyridine, 2-(4-methoxyphenyl)amino-3-aminopyridine,2,3-diamino-6-methoxypyridine,2-(β-methoxyethyl)amino-3-amino-6-methoxypyridine, 3,4-diaminopyridineand the acid addition salts of any of the foregoing.

[0113] Non-limiting examples of pyrimidine derivatives include compoundsdescribed, for example, in German Patent DE 2 359 399, Japanese PatentsJP 88-169 571 and JP 91-10659, and Patent Application WO 96/15765, thedisclosures of which are incorporated herein by reference, such as2,4,5,6-tetraaminopyrimidine, 4-hydroxy-2,5,6-triaminopyrimidine,2-hydroxy-4,5,6-triaminopyrimidine, 2,4-dihydroxy-5,6-diaminopyrimidine,2,5,6-triaminopyrimidine, and pyrazolopyrimidine derivatives such asthose mentioned in patent application FR-A-2 750 048, the disclosure ofwhich is incorporated herein by reference, such aspyrazolo[1,5-a]pyrimidine-3,7-diamine,2,5-dimethylpyrazolo[1,5-a]pyrimidine-3,7-diamine,pyrazolo[1,5-a]pyrimidine-3,5-diamine, 2,7-dimethylpyrazolo[1,5-a]pyrimidine-3,5-diamine, 3-aminopyrazolo[1 ,5-a]pyrimidin-7-ol,3-aminopyrazolo[1,5-a]pyrimidin-5-ol,2-(3-aminopyrazolo[1,5-a]pyrimidin-7-ylamino)ethanol,2-(7-aminopyrazolo[1,5-a]pyrimidin-3-ylamino)ethanol,2-[(3-aminopyrazolo[1,5-a]pyrimidin-7-yl)(2-hydroxyethyl)amino]ethanol,2-[(7-aminopyrazolo[1,5-a]pyrimidin-3-yl)(2-hydroxyethyl)amino]ethanol,5,6-dimethylpyrazolo[1,5-a]pyrimidine-3,7-diamine,2,6-dimethylpyrazolo[1,5-a]pyrimidine-3,7-diamine,2,5,N7,N7-tetramethylpyrazolo[1,5-a]pyrimidine-3,7-diamine,3-amino-5-methyl-7-imidazolylpropylaminopyrazolo[1,5-a]pyrimidine, andthe addition salts, tautomeric forms, (when a tautomeric equilibriumexists) and acid addition salts of any of the foregoing.

[0114] Further non-limiting examples of pyrazole derivatives includecompounds described in German Patents DE 3 843 892 and DE 4 133 957 andPatent Applications WO 94/08969, WO 94/08970, FR-A-2 733 749 and DE 19543 988, the disclosures of which are incorporated hereby by reference,such as 4,5-diamino-1-methylpyrazole, 3,4-diaminopyrazole,4,5-diamino-1-(4′-chlorobenzyl)pyrazole,4,5-diamino-1-(β-hydroxy-ethyl)pyrazole,4,5-diamino-1,3-dimethylpyrazole, 4,5-diamino-3-methyl-1-phenylpyrazole,4,5-diamino-1-methyl-3-phenylpyrazole,4-amino-1,3-dimethyl-5-hydrazinopyrazole,1-benzyl-4,5-diamino-3-methylpyrazole,4,5-diamino-3-tert-butyl-1-methylpyrazole,4,5-diamino-1-tert-butyl-3-methylpyrazole,4,5-diamino-1-(β-hydroxyethyl)-3-methylpyrazole,4,5-diamino-1-ethyl-3-methylpyrazole,4,5-diamino-1-ethyl-3-(4′-methoxyphenyl)pyrazole,4,5-diamino-1-ethyl-3-hydroxymethylpyrazole,4,5-diamino-3-hydroxymethyl-1-methylpyrazole,4,5-diamino-3-hydroxymethyl-1-isopropylpyrazole,4,5-diamino-3-methyl-1-isopropylpyrazole,4-amino-5-(2′-aminoethyl)amino-1,3-dimethylpyrazole,3,4,5-triaminopyrazole, 1-methyl-3,4,5-triaminopyrazole,3,5-diamino-1-methyl-4-methylamino-pyrazole,3,5-diamino-4-(β-hydroxyethyl)amino-1-methylpyrazole, and the acidaddition salts of any of the foregoing.

[0115] According to the present invention, the at least one oxidationbase may be present in the composition in an amount generally rangingfrom 0.0005% to 12% by weight relative to the total weight of the dyecomposition, such as from 0.005% to 6% by weight.

[0116] The dye composition according to the present invention mayoptionally further comprise at least one additional coupler differentfrom the indolizine derivatives of formula (I) and may optionallyfurther comprise at least one direct dye, for example, to vary and/orenrich the shade obtained using the at least one oxidation base withhighlights.

[0117] The at least one additional coupler which can be used in the dyecomposition according to with the present invention may be chosen fromcouplers, such as, for example, meta-phenylenediamines,meta-aminophenols, meta-diphenols and heterocyclic couplers such as, forexample, indole derivatives, indoline derivatives, benzimidazolederivatives, benzomorpholine derivatives, sesamol derivatives, pyridinederivatives, pyrimidine derivatives, pyrazole derivatives and the acidaddition salts thereof.

[0118] In one embodiment, the at least one additional coupler is chosenfrom 2-methyl-5-aminophenol, 5-N-(β-hydroxyethyl)amino-2-methylphenol,3-aminophenol, 1,3-dihydroxybenzene, 1,3-dihydroxy-2-methylbenzene,4-chloro-1,3-dihydroxybenzene, 2,4-diamino-1-(β-hydroxyethyloxy)benzene,2-amino-4-(β-hydroxyethylamino)-1-methoxybenzene, 1,3-diaminobenzene,1,3-bis(2,4-diaminophenoxy)propane, sesamol,1-amino-2-methoxy-4,5-methylenedioxybenzene, α-naphthol,2-methyl-1-naphthol, 6-hydroxyindole, 4-hydroxyindole,4-hydroxy-N-methylindole, 6-hydroxyindoline,2,6-dihydroxy-4-methylpyridine, 1-H-3-methylpyrazol-5-one,1-phenyl-3-methylpyrazol-5-one and the addition salts of any of theforegoing.

[0119] When present, the at least one additional coupler may be presentin the composition in an amount generally ranging 0.0001% to 10% byweight relative to the total weight of the dye composition, such as from0.005% to 5% by weight.

[0120] According to the present invention, the acid addition salts maybe chosen from hydrochlorides, hydrobromides, sulphates, tartrates,lactates and acetates.

[0121] The medium suitable for oxidation dyeing, or support, accordingto the present invention may be chosen from water and a mixture of waterand at least one organic solvent in order to dissolve the compoundswhich might not be sufficiently soluble in water alone. Non-limitingexamples of the at least one organic solvent includes C₁-C₄ alkanolssuch as ethanol and isopropanol; glycerol; glycols and glycol etherssuch as 2-butoxyethanol, propylene glycol, propylene glycol monomethylether, diethylene glycol, diethylene glycol monomethyl ether; aromaticalcohols such as benzyl alcohol and phenoxyethanol; and analogoussolvents.

[0122] According to the present invention, the at least one organicsolvent maybe present in the composition in an amount generally rangingfrom 1% to 40% by weight relative to the total weight of the dyecomposition, such as from 5% to 30% by weight.

[0123] The pH of the dye composition in accordance with the presentinvention generally ranges from 3 to 12. It can be adjusted to thedesired value by means of at least one agent commonly used in dyeingkeratin fibres chosen from acidifying agents and basifying agents.

[0124] Non-limiting examples of acidifying agents include inorganicacids and organic acids such as hydrochloric acid, orthophosphoric acid,carboxylic acids (such as tartaric acid, citric acid and lactic acid)and sulphonic acids.

[0125] Non-limiting examples of basifying agents include aqueousammonia, alkaline carbonates, alkanolamines such as mono-, di- andtriethanolamines and derivatives thereof, sodium hydroxide, potassiumhydroxide and compounds of formula (VIII):

[0126] wherein:

[0127] R₂₈ is chosen from divalent propylene residues, optionallysubstituted with at least one radical chosen from hydroxyl radicals andC₁-C₄ alkyl radicals; R₂₄, R₂₅, R₂₆ and R₂₇, which may be identical ordifferent, are each chosen from a hydrogen atom, C₁-C₄ alkyl radicalsand C₁-C₄ hydroxyalkyl radicals.

[0128] According to the present invention, the dye composition mayfurther comprise at least one adjuvant chosen from adjuvantsconventionally used in hair dyeing compositions, such as anionicsurfactants, cationic surfactants, nonionic surfactants, amphotericsurfactants, zwitterionic surfactants, anionic polymers, cationicpolymers, nonionic polymers, amphoteric polymers, zwitterionic polymers,inorganic thickeners, organic thickeners, antioxidants, penetrationagents, sequestering agents, fragrances, buffers, dispersing agents,conditioners, such as, for example, silicones, film-forming agents,preserving agents and opacifiers.

[0129] Needless to say, a person skilled in the art will take care tochoose any optional additional compound(s) such that the advantageousproperties associated with the inventive dye compositions are not, ornot substantially, adversely affected by the addition(s) envisaged.

[0130] According to the present invention, the dye composition may beprovided in various forms, such as in the form of a liquid, a cream or agel, or in any other form suitable for dyeing keratin fibres, such ashuman hair.

[0131] Another subject of the present invention is a process foroxidation dyeing of keratin fibres comprising applying to said keratinfibres for a sufficient time to obtain a desired color at least one dyecomposition comprising, in a medium suitable for dyeing, (i) at leastone coupler chosen from indolizine derivatives of formula (i) and acidaddition salts thereofp; and (ii) at least one oxidation base. In oneembodiment, the keratin fibres are chosen from human keratin fibres. Inanother embodiment, the human keratin fibres are hair.

[0132] In another embodiment, the at least one dye composition isapplied to the keratin fibres, and the desired color may be developed ata pH chosen from acidic, neutral or alkaline pH. Further, the at leastone dye composition may further comprise at least one oxidizing agentwhich may be added to the at least one dye composition at the time ofapplication, and/or which may be present in at least one oxidizingcomposition. In one embodiment, the at least one oxidizing compositionmay be applied simultaneously with said at least one dye composition,while in another embodiment, the at least one oxidizing composition maybe applied to the keratin fibres sequentially with the at least one dyecomposition.

[0133] In a further embodiment, the at least one dye composition ismixed, at the time of use, with at least one oxidizing compositioncomprising, in a medium appropriate for dyeing, at least one oxidizingagent present in an amount sufficient to develop a desired coloration.The mixture obtained may subsequently be applied to the keratin fibresand may be left to stand for 3 to 50 minutes, such as for 5 to 30minutes. In yet another embodiment, the fibres are rinsed, and mayoptionally be washed with a shampoo, rinsed again and dried.

[0134] According to the present invention, the at least one oxidizingagent may be chosen from oxidizing agents conventionally used for theoxidation dyeing of keratin fibres, such as hydrogen peroxide, ureaperoxide, alkali metal bromates, persalts such as perborates andpersulphates, peracids and enzymes such as peroxidases, laccases,tyrosinases and oxidoreductases (such as pyranose oxidases, glucoseoxidases, glycerol oxidases, lactate oxidases, pyruvate oxidases anduricases).

[0135] The pH of the at least one oxidizing composition comprising theat least one oxidizing agent after mixing with the at least one dyecomposition may generally range from 3 to 12, such as from 5 and 11.Further, the pH may be adjusted to a desired value by means of at leastone agent chosen from acidifying and basifying agents commonly in dyeingkeratin fibres and as defined above.

[0136] The at least one oxidizing composition as defined above may alsocontain at least one adjuvant conventionally used in hair dyeingcompositions and as defined above.

[0137] The composition which is applied to the keratin fibres may be invarious forms, such as in the form of a liquid, a cream or a gel or anyother form suitable for carrying out dyeing of keratin fibres, such ashuman hair.

[0138] The present invention also provides a multi-compartment device orkit or any other packaging system, comprising a first compartmentcontaining a first composition comprising at least one dye compositionas defined above and a second compartment containing a secondcomposition comprising at least one oxidizing composition as definedabove. These devices may be equipped with a means allowing the desiredmixture to be deposited on the hair, such as the devices described inFrench Patent FR-2 586 913, the disclosure of which is incorporatedherein.

[0139] Finally, this invention provides certain novel indolizinederivatives of formula (I). These novel indolizine derivatives, and theacid addition salts thereof, correspond to formula (I) as defined above,with the following additional conditions:

[0140] Z cannot be chosen from the cationic groups of formula (IV) asdefined above;

[0141] providing that4-methyl-4-[2-(2-phenyl-1-indolizinyl)ethyl]morpholinium bromide isexcluded.

[0142] The excluded compounds are known in the pharmaceutical field, asseen in patents U.S. Pat. No. 3,717,644 and U.S. Pat. No. 3,642,807.

[0143] In one embodiment, these novel indolizine derivatives may bechosen from:

[0144] 1-methyl-2-[2-(7-methyl-2-phenylindolizin-3-yl)ethyl]pyridiniummethyl sulphate;

[0145]3-methyl-1-[2-(7-methyl-2-phenylindolizin-3-yl)-2-oxoethyl]-3H-imidazol-1-iumchloride;

[0146]3-methyl-1-[2-(2-methylindolizin-3-yl)-2-oxoethyl]-3H-imidazol-1-iumchloride;

[0147]1-{2-[2-(4-methoxyphenyl)-8-methylindolizin-3-yl]-2-oxoethyl}-3-methyl-3H-imidazol-1-iumchloride;

[0148]3-methyl-1-{2-[8-methyl-2-(3-nitrophenyl)indolizin-3-yl]-2-oxoethyl}-3H-imidazol-1-ium chloride;

[0149] 1-{2-[2-(3-nitrophenyl)indolizin-3-yl]-2-oxoethyl}pyridiniumchloride;

[0150] 1-[2-oxo-2-(2-phenylindolizin-3-yl)ethyl]pyridinium chloride;

[0151] 1-[2-oxo-2-(2-m-tolylindolizin-3-yl)ethyl]pyridinium chloride;

[0152]1-[2-(8,1-{2-[2-(4-methoxyphenyl)-8-methylindolizin-3-yl]-2-oxoethyl}-2-methylpyridiniumchloride;

[0153] 2-phenylindolizin-3-yl )-2-oxoethyl]pyridinium methyl chloride;

[0154] [2-(8-methyl-2-phenylindolizin-3-yl)-2-oxoethyl] pyridiniumchloride;

[0155]2-methyl-1-{2-[2-(3-nitrophenyl)indolizin-3-yl]-2-oxoethyl}pyridiniumchloride;

[0156] 2-methyl-1-[2-oxo-2-(2-phenylindolizin-3-yl)ethyl]pyridiniumchloride;

[0157]2-methyl-1-{2-[8-methyl-2-(3-nitrophenyl)indolizin-3-yl]-2-oxoethyl}pyridiniumchloride;

[0158]2-methyl-1-[2-(8-methyl-2-phenylindolizin-3-yl)-2-oxoethyl]pyridiniumchloride;

[0159]3-methoxycarbonyl-1-{2-[2-(3-nitrophenyl)indolizin-3-yl]-2-oxoethyl}pyridiniumchloride;

[0160]3-methoxycarbonyl-1-[2-oxo-2-(2-phenylindolizin-3-yl)ethyl]pyridiniumchloride;

[0161]3-methoxycarbonyl-1-{2-[2-(4-methoxyphenyl)-8-methylindolizin-3-yl]-2-oxoethyl}pyridiniumchloride;

[0162]3-methoxycarbonyl-1-{2-[8-methyl-2-(3-nitropheny)indolizin-3-yl]-2-oxoethyl}pyridiniumchloride;

[0163]3-methoxycarbonyl-1-[2-(8-methyl-2-phenylindolizin-3-yl)-2-oxoethyl]pyridiniumchloride;

[0164] and the acid addition salts of any of the foregoing. The additionsalts with an acid of the above novel compounds are chosen from thosedefined above for the compounds of formula (I).

[0165] These specific compounds may be prepared according to thesynthetic process of indolizines comprising the step of reactingcompounds chosen from alkyl-2 pyridine and aralkyl-2 pyridine with ahaloacetone thus producing a pyridinium salt (Chichibabin, Ber. 1927,60, 1607; Borrows, Holland, Kenyon, J. Chem. Soc. 1946, 1069). Byreacting the salt with a base such as sodium bicarbonate in aqueousmedium, indolinine is produced by cyclisation. Other methods forproducing the indolizine nucleus are disclosed in T. Uchida et K.Matsumoto, Synthesis, 1976, 209-236. These compounds are thenquaternized according to known conventional quaternization methods.

[0166] The compounds thus obtained can be purified by known methods suchas distillation and crystallisation.

[0167] Other than in the operating example, or where otherwiseindicated, all numbers expressing quantities of ingredients, reactionconditions, and so forth used in the specification and claims are to beunderstood as being modified in all instances by the term “about.”Accordingly, unless indicated to the contrary, the numerical parametersset forth in the following specification and attached claims areapproximations that may vary depending upon the desired propertiessought to be obtained by the present invention. At the very least, andnot as an attempt to limit the application of the doctrine ofequivalents to the scope of the claims, each numerical parameter shouldbe construed in light of the number of significant digits and ordinaryrounding approaches.

[0168] Notwithstanding that the numerical ranges and parameters settingforth the broad scope of the invention are approximations, the numericalvalues set forth in the specific examples are reported as precisely aspossible. Any numerical value, however, inherently contain certainerrors necessarily resulting from the standard deviation found in theirrespective testing measurements. The following examples are intended toillustrate the invention without limiting the scope as a result.

PREPARATION EXAMPLES Preparation Example 1 Synthesis of1-methyl-2-[2-(7-methyl-2-phenylindolizin-3-yl)ethyl]pyridinium MethylSulphate

[0169] Starting with the 7-methyl-2-phenylindolizine obtained accordingto the synthetic method of Chichibabin (Chichibabin Ber. 1927, 60,1607), a catalytic addition of vinylpyridine was performed according tothe method described by Pentimalli and Bozzini Ann. Chimica 1966, 56,752. The 7-methyl-2-phenyl-3-(2-pyrid-2-ylethyl)indolizine thus obtainedwas treated with 3 molar equivalents of dimethyl sulphate in refluxingethyl acetate. After reaction for two hours, the precipitate formed wasfiltered off and recrystallized from isopropyl alcohol, and the1-methyl-2-[2-(7-methyl-2-phenylindolizin-3-yl)ethyl]pyridinium methylsulphate was obtained in the form of a beige-coloured solid melting at atemperature of 204° C. (Kofler).

[0170] The ¹H NMR analysis (DMSO-d₆, 400 MHz) (δ ppm) was as follows:2.28 (s, 3H); 3.33 (t, 2H); 3.37 (s, 3H); 3.56 (t, 2H); 3.91 (s, 3H);6.35 (s, 1 H); 6.53 (dd, 1 H); 7.22 (m, 1 H); 7.26 (m, 1 H); 7.30 (m,2H); 7.35 (m, 2H); 7.79 (dd, 1H); 7.84 (ddd, 1 H); 8.22 (d, 1 H); 8.30(ddd, 1 H); 8.78 (dd, 1 H).

Preparation Example 2 Synthesis of3-methyl-1-[2-(7-methyl-2-phenylindolizin-3-yl)-2-oxoethyl]-3H-imidazol-1-iumChloride

[0171] Starting with the 7-methyl-2-phenylindolizine obtained accordingto the synthetic method of Chichibabin (Chichibabin Ber. 1927, 60,1607),acylation with chloroacetyl chloride was performed under the followingconditions:

[0172] 2.8 g (0.025 mol) of chloroacetyl chloride were added to asolution of 5 g (0.024 mol) of 7-methyl-2-phenylindolizine and 2.4 g(0.024 mol) of triethylamine in 300 ml of 1,2-dichloroethane. The mediumwas refluxed for 2 h 30 min and then cooled to room temperature. Thereaction medium was washed 3 times with 100 ml of water and once with100 ml of saturated sodium chloride solution. The organic phase wasdried over sodium sulphate, filtered and concentrated on a rotaryevaporator. The oil obtained was used in the following step withoutfurther purification.

[0173] The oil obtained was dissolved in 110 ml of ethyl acetate and themixture was brought to reflux. 10 g (0.122 mol) of N-methylimidazolewere added and refluxing was continued for one hour. The medium was thencooled to room temperature and the precipitate was filtered off, washedwith ethyl acetate and then recrystallized from isopropyl alcohol. Avery pale grey light solid melting at 250° C. (Kofler) was obtained.

[0174] The ¹H NMR analysis (DMSO-d₆, 400 MHz) (δ ppm) was as follows:2.40 (s, 3H); 3.89 (s, 3H); 5.04 (s, 2H); 6.59 (s, 1H); 7.02 (dd, 1H);7.48-7.64 (m, 7H); 7.72 (dd, 1H); 9.14 (dd, 1 H); 9.71 (d, 1 H).

Preparation Example 3 Synthesis of3-methyl-1-[2-(2-methylindolizin-3-yl)-2-oxoethyl]-3H-imidazol-1-iumChloride

[0175] The 2-methylindolizine obtained according to the Chichibabinsynthesis was treated with chloroacetyl chloride as described previouslyin Preparation Example 2 above. The green powder obtained was used inthe following quaternization step without further purification.

[0176] 7.9 g of this green powder (0.0383 mol) were dissolved in 150 mlof ethyl acetate. 9.6 g (0.116 mol) of N-methylimidazole were added andthe medium was brought to reflux. After refluxing for 3 hours, a further9.6 g (0.116 mol) of N-methylimidazole were added. Refluxing wascontinued for 1 hour and the reaction medium was cooled to roomtemperature. The solid which precipitated was filtered off, washed withethyl acetate and then recrystallized from isopropyl alcohol. Abeige-coloured solid melting at a temperature above 260° C. (Kofler) wasobtained.

[0177] The ¹H NMR analysis (DMSO-d₆, 400 MHz) (δ ppm) was as follows:2.69 (s, 3H); 3.98 (s, 3H); 5.90 (s, 2H); 6.62 (s, 1 H); 7.03 (dd, 1 H);7.76 (unresolved multiplet, 3H); 9.20 (d, 1 H); 9.79 (d, 1 H).

DYEING EXAMPLES Examples 1 to 4 of Dyeing in Alkaline Medium

[0178] The dye compositions below, in accordance with the invention,were prepared: EXAMPLE 1 2 3 4 1-Methyl-2-[2-(7-methyl- 3 × 10⁻³ 3 ×10⁻³ — — 2-phenylindolizin-3-yl) mol mol ethyl]pyridinium methylsulphate (coupler of formula (I)) 3-Methyl-1-[2[(7-methyl- — — 3 × 10⁻³3 × 10⁻³ 2-phenylindolizin-3-yl)- mol mol 2-oxoethyl]-3H- imidazol-1-iumchloride (coupler of formula (I)) para-Tolylenediamine 3 × 10⁻³ — 3 ×10⁻³ — (oxidation base) mol mol 3,7-Diaminopyrazolopy- — 3 × 10⁻³ — 3 ×10⁻³ rimidinedihydrochloride mol mol (oxidation base) Common dye support(*) (*) (*) (*) Demineralized water qs 100 g 100 g 100 g 100 g (*)Common dye support: Ethanol   18 g Aqueous ammonia containing 20% NH₃  10 g Sodium metabisulphite 0.205 g Sequestering agent qs

[0179] At the time of use, the above dye compositions were mixed weightfor weight with a 20-volumes hydrogen peroxide solution (6% by weight)of pH 3.

[0180] The mixture obtained had a pH of about 10, and was applied for 30minutes to locks of natural grey hair containing 90% white hairs. Thelocks were then rinsed, washed with shampoo, rinsed again and thendried.

[0181] The hair was dyed in a shade given in the table below. EXAMPLESHADE OBTAINED 1 Very matt golden blond 2 Very ashen natural blond 3Slightly ashen golden blond 4 Very ashen iridescent blond

What is claimed is:
 1. A composition for dyeing keratin fibres, whereinthe composition comprises, in a medium which is suitable for dyeing: (i)at least one oxidation base; and (ii) at least one coupler chosen fromindolizine derivatives of formula (I) and the acid addition saltsthereof:

in which: n may be an integer from 0 to 4; R₁ and R₃, which may beidentical or different, are each chosen from hydrogen atoms; halogenatoms; Z groups; C₁-C₄ alkyl radicals; C₁-C₄ alkoxy radicals; C₁-C₄monohydroxyalkyl radicals; C₂-C₄ polyhydroxyalkyl radicals; C₁-C₄aminoalkyl radicals; acetylamino radicals; acetylamino-(C₁-C₄)alkylradicals; (C₁-C₄)alkoxy(C₁-C₄)alkyl radicals;mono(C₁-C₄)alkylamino(C₁-C₄)alkyl radicals;di(C₁-C₄)alkylamino(C₁-C₄)alkyl radicals; aminocarboxy(C₁-C₄)alkylradicals; acetyl(C₁-C₄)alkylamino(C₁-C₄)alkyl radicals; and aromaticrings which are optionally substituted with at least one radical chosenfrom halogen atoms, C₁-C₄ alkyl radicals, trifluoro-methyl radicals,C₁-C₄ alkoxy radicals, amino radicals, mono- and disubstituted aminoradicals wherein the substituent is chosen from C₁-C₄ alkyl radicals,(C₁-C₄)alkylamino(C₁-C₄)alkyl radicals, di(C₁-C₄)alkylamino(C₁-C₄)alkylradicals, carboxyl radicals and sulphoxy radicals; R₃ may optionallyfurther be chosen from 5- and 6-membered unsaturated heterocycles; R₂and R₄, which may be identical or different, are each chosen fromhydrogen atoms; halogen atoms, Z groups; C₁-C₄ alkyl radicals, C₁-C₄monohydroxyalkyl radicals, C₂-C₄ polyhydroxyalkyl radicals, C₁-C₄aminoalkyl radicals, mono(C₁-C₄)-alkylamino(C₁-C₄)alkyl radicals,di(C₁-C₄)alkyl-amino(C₁-C₄)alkyl radicals, carboxyl radicals, cyanoradicals, carboxy(C₁-C₄)alkyl radicals, nitro radicals and 5- and6-membered aromatic rings which are optionally substituted with at leastone radical chosen from halogen atoms, C₁-C₄ alkyl radicals,trifluoromethyl radicals, C₁-C₄ alkoxy radicals, amino radicals andmono- and disubstituted amino radicals wherein the substituent is chosenfrom C₁-C₄ alkyl radicals, (C₁-C₄)alkylamino-(C₁-C₄)alkyl radicals,di(C₁-C₄)alkylamino-(C₁-C₄)alkyl radicals, carboxyl radicals andsulphoxy radicals; Z is chosen from the following unsaturated cationicgroups of formulae (II) and (III) below, and the saturated cationicgroups of formula (IV) below:

in which: D is a linker arm which is chosen from linear and branchedalkylene chains which may be interrupted by at least one hetero atom,and which may be substituted with at least one substituent chosen fromhydroxyl and C₁-C₆ alkoxy radicals, and which may bear at least oneketone function; the ring members E, G, J, L and M, which may beidentical or different, are chosen from carbon, oxygen, sulphur andnitrogen atoms; b is an integer from 0 to 4; m is an integer from 0 to5; the radicals R, which may be identical or different, are chosen froma second group Z, which may be identical to or different from the firstgroup Z, halogen atoms, hydroxyl radicals, C₁-C₆ alkyl radicals, C₁-C₆monohydroxyalkyl radicals, C₂-C₆ polyhydroxyalkyl radicals, nitroradicals, cyano radicals, cyano(C₁-C₆)alkyl radicals, C₁-C₆ alkoxyradicals, tri(C₁-C₆)alkylsilane(C₁-C₆)alkyl radicals, amido radicals,aldehydo radicals, carboxyl radicals, (C₁-C₆)alkylcarbonyl radicals,thio radicals, C₁-C₆ thioalkyl radicals, C₁-C₆ alkylthio radicals, aminoradicals, amino radicals protected with at least one group chosen from(C₁-C₆)alkylcarbonyls, carbamyls and C₁-C₆ alkylsulphonyl radicals; NHR″and NR″R′″ groups in which R″ and R′″, which may be identical ordifferent, are chosen from C₁-C₆ alkyl radicals, C₁-C₆ monohydroxyalkylradicals and C₂-C₆ polyhydroxyalkyl radicals; R₅ is chosen from C₁-C₆alkyl radicals, C₁-C₆ mono-hydroxyalkyl radicals, C₂-C₆ polyhydroxyalkylradicals, cyano(C₁-C₆)alkyl radicals, tri(C₁-C₆)-alkylsilane(C₁-C₆)alkylradicals, (C₁-C₆)alkoxy-(C₁-C₆)alkyl radicals, carbamyl(C₁-C₆)alkylradicals, (C₁-C₆)alkylcarboxy(C₁-C₆)alkyl radicals, benzyl radicals andsecond Z groups which may be identical to or different from the first Zgroups; R₆, R₇ and R₈, which may be identical or different, are eachchosen from C₁-C₆ alkyl radicals, C₁-C₆ monohydroxyalkyl radicals, C₂-C₆polyhydroxyalkyl radicals, (C₁-C₆)alkoxy(C₁-C₆)alkyl radicals,cyano(C₁-C₆)alkyl radicals, aryl radicals, benzyl radicals,amido(C₁-C₆)alkyl radicals, tri(C₁-C₆)alkylsilane(C₁-C₆)alkyl radicalsand C₁-C₆ aminoalkyl radicals in which the amine is protected with atleast one group chosen from (C₁-C₆)alkylcarbonyls, carbamyls and C₁-C₆alkylsulphonyl radicals; two of the radicals R₆, R₇ and R₈, may alsoform, together with the nitrogen atom to which they are attached, 5- and6-membered saturated carbon-based rings and rings containing at leastone hetero atom, it being possible for the said ring to be optionallysubstituted with at least one substituent chosen from halogen atoms,hydroxyl radicals, C₁-C₆ alkyl radicals, C₁-C₆ monohydroxyalkylradicals, C₂-C₆ polyhydroxyalkyl radicals, nitro radicals, cyanoradicals, cyano(C₁-C₆)alkyl radicals, C₁-C₆ alkoxy radicals,tri(C₁-C₆)alkylsilane(C₁-C₆)alkyl radicals, amido radicals, aldehydoradicals, carboxyl radicals, keto(C₁-C₆)alkyl radicals, thio radicals,C₁-C₆ thioalkyl radicals, C₁-C₆ alkylthio radicals, amino radicals andamino radical protected with at least one group chosen from(C₁-C₆)alkylcarbonyls, carbamyls and C₁-C₆ alkylsulphonyl radicals; oneof the radicals R₆, R₇ and R₈ may optionally be chosen from second Zgroups, which may be identical to or different from the first Z groups;R₉ is chosen from C₁-C₆ alkyl radicals; C₁-C₆ monohydroxyalkyl radicals;C₂-C₆ polyhydroxyalkyl radicals; aryl radicals; benzyl radicals; C₁-C₆aminoalkyl radicals, C₁-C₆ aminoalkyl radicals wherein the amine isprotected by at least one group chosen from (C₁-C₆)alkylcarbonyls,carbamyls and C₁-C₆ alkylsulphonyl radicals; carboxy(C₁-C₆)alkylradicals; cyano(C₁-C₆)alkyl radicals; carbamyl(C₁-C₆)alkyl radicals;C₁-C₆ trifluoroalkyl radicals; tri(C₁-C₆)alkylsilane(C₁-C₆)alkylradicals; sulphonamido(C₁-C₆)alkyl radicals;(C₁-C₆)alkylcarboxy(C₁-C₆)alkyl radicals;(C₁-C₆)alkylsulphinyl(C₁-C₆)alkyl radicals;(C₁-C₆)alkylsulphonyl(C₁-C₆)alkyl radicals; (C₁-C₆)alkylketo(C₁-C₆)alkylradicals; N-(C₁-C₆)alkylcarbamyl(C₁-C₆)alkyl radicals; andN-(C₁-C₆)alkylsulphonamido(C₁-C₆)alkyl radicals; a and y are integersequal to 0 or 1; with the following provisos: in the unsaturatedcationic groups of formula (II): when a=0, the linker arm D is attachedto the nitrogen atom, when a=1, the linker arm D is attached to one ofthe ring members E, G, J and L, y cannot take the value 1 except: 1)when the ring members E, G, J and L simultaneously represent a carbonatom, and when the radical R₅ is attached to the nitrogen atom of theunsaturated ring; or alternatively 2) when at least one of the ringmembers E, G, J and L represents a nitrogen atom to which the radical R₅is attached; when b is at least 2, two adjacent radicals R may also formtogether a ring chosen from unsaturated 5- and 6-membered carbon-basedrings and rings containing at least one hetero atom; in the unsaturatedcationic groups of formula (III): when a=0, the linker arm D is attachedto the nitrogen atom, when a=1, the linker arm D is attached to one ofthe ring members E, G, J, L and M, y cannot take the value 1 except whenat least one of the ring members E, G, J, L and M represents a divalentatom, and when the radical R₅ is attached to the nitrogen atom of theunsaturated ring; when m is at least 2, two adjacent radicals R may alsoform together unsaturated 5- and 6-membered carbon-based rings and ringscontaining at least one hetero atom; in the cationic groups of formula(IV): when a=0, the linker arm D is attached to the nitrogen atombearing the radicals R₆ to R₈, when a=1, two of the radicals R₆ to R₈form, together with the nitrogen atom to which they are attached,saturated 5- and 6-membered rings as defined above, and the linker arm Dis attached to a carbon atom of the said saturated ring; X⁻ is chosenfrom monovalent and divalent anions; it being understood that: at leastone of the radicals R₁ and R₃ represents a hydrogen atom; and the numberof cationic groups Z is at least equal to
 1. 2. The compositionaccording to claim 1 , wherein R₃ is an unsaturated heterocycle chosenfrom pyrrole rings, pyridine rings, pyrimidine rings, imidazole rings,pyrazole rings, oxazole rings, thiazole rings, triazole rings,pyrazolotriazole rings, pyrazoloimidazole rings, pyrrolotriazole rings,pyrazolopyrimidine rings, pyrazolopyridine rings, benzimidazole rings,benzoxazole rings, benzothiazole rings, indole rings, indoline rings,indolidine rings, isoindolidine rings, benzotriazoline rings, pyrazinerings, oxazine rings, triazine rings, quinoline rings,tetrahydroquinoline rings, benzimidazolidine rings and benzopyrimidinerings.
 3. The composition according to claim 1 , wherein the rings inthe unsaturated Z groups of formula (II) are chosen from pyrrole rings,imidazole rings, pyrazole rings, oxazole rings, thiazole rings, triazolerings, pyrazoltriazolinium rings, pyrazoloimidazolinium rings,pyrrolotriazolinium rings, pyrazolopyrimidinium rings,pyrazolopyridinium rings, benzimidazolinium rings, benzoxazoliniumrings, benzothiazolinium rings, indolinium rings, indolidinium rings,isoindolinium rings, indazolinium rings and benzotriazolinium rings. 4.The composition according to claim 1 , wherein the rings in theunsaturated Z groups of formula (III) are chosen from pyridine rings,pyrimidine rings, pyrazine rings, oxazine rings, triazine rings,quinolinium rings, tetrahydroquinolinium rings, benzimidazolidiniumrings and benzopyrimidinium rings.
 5. The composition according to claim1 , wherein X- is chosen from halides, hydroxides, hydrogen sulphatesand (C₁-C₆)alkyl sulphates.
 6. The composition according to claim 1 ,(wherein the indolizine derivatives of formula (I) are chosen from:N,N-dimethyl-2-phenyl-N-(phenylmethyl)-1-indolizinepropanaminium;N,N,N-trimethyl-2-phenyl-1-indolizinethanaminiumN,N,N-trimethyl-2-phenyl-1-indolizinepropanaminium bromide;4-methyl-4-[2-(2-phenyl-1-indolizinyl )ethyl]morpholinium bromide;N,N-dimethyl-2-phenyl-N-(phenylmethyl)-1-indolizinepropanaminiumnitrate;N,N-dimethyl-2-phenyl-N-(phenylmethyl)-1-indolizinepropanaminiumchloride; N,N,N-trimethyl-2-phenyl-1-indolizinethanaminium methylsulphate; trimethyl[2-(2-phenyl-1-indolizinyl)ethyl]ammonium iodide;trimethyl[2-(2-phenyl-l -indolizinyl)ethyl]ammonium bromide;1-methyl-2-[2-(7-methyl-2-phenylindolizin-3-yl)ethyl]pyridinium methylsulphate;3-methyl-1-[2-(7-methyl-2-phenylindolizin-3-yl)-2-oxoethyl]-3H-imidazol-1-iumchloride;3-methyl-1-[2-(2-methylindolizin-3-yl)-2-oxoethyl]-3H-imidazol-1-iumchloride;1-{2-[2-(4-methoxyphenyl)-8-methylindolizin-3-yl]-2-oxoethyl}-3-methyl-3H-imidazol-1-iumchloride;3-methyl-1-{2-[8-methyl-2-(3-nitrophenyl)indolizin-3-yl]-2-oxoethyl}-3H-imidazol-1-ium chloride;1-{2-[2-(3-nitrophenyl)indolizin-3-yl]-2-oxoethyl}pyridinium chloride;1-[2-oxo-2-(2-phenylindolizin-3-yl)ethyl]pyridinium chloride;1-[2-oxo-2-(2-m-tolylindolizin-3-yl)ethyl]pyridinium chloride;1-[2-(8,1-{2-[2-(4-methoxyphenyl)-8-methylindolizin-3-yl]-2-oxoethyl}-2-methylpyridiniumchloride; 2-phenylindolizin-3-yl )-2-oxoethyl]pyridinium methylchloride; [2-(8-methyl-2-phenylindolizin-3-yl)-2-oxoethyl]pyridiniumchloride;2-methyl-1-{2-[2-(3-nitrophenyl)indolizin-3-yl]-2-oxoethyl}pyridiniumchloride; 2-methyl-1-[2-oxo-2-(2-phenylindolizin-3-yl)ethyl]pyridiniumchloride;2-methyl-1-{2-[8-methyl-2-(3-nitrophenyl)indolizin-3-yl]-2-oxoethyl}pyridiniumchloride;2-methyl-1-[2-(8-methyl-2-phenylindolizin-3-yl)-2-oxoethyl]pyridiniumchloride;3-methoxycarbonyl-1-{2-[2-(3-nitropheny)indolizin-3-yl]-2-oxoethyl}pyridiniumchloride; 3-methoxycarbonyl-1-[2-oxo-2-(2-phenylindolizin-3-yl)ethyl]pyridinium chloride; 3-methoxycarbonyl-1-{2-[2-(4-methoxyphenyl)-8-methylindolizin-3-yl]-2-oxoethyl}pyridinium chloride;3-methoxycarbonyl-1-{2-[2-(3-nitrophenyl)indolizin-3-yl]-2-oxoethyl}pyridiniumchloride;3-methoxycarbonyl-1-[2-(8-methyl-2-phenylindolizin-3-yl)-2-oxoethyl]pyridiniumchloride; and the addition salts thereof with an acid.
 7. Thecomposition according to claim 1 , wherein said at least one coupler ispresent in an amount ranging from 0.0005% to 12% by weight relative tothe total weight of said composition.
 8. The composition according toclaim 7 , wherein said at least one coupler is present in an amountranging from 0.005% to 6% by weight relative to the total weight of saidcomposition.
 9. The composition according to claim 1 , wherein said atleast one oxidation base is chosen from para-phenylenediamines, doublebases, para-aminophenols, ortho-aminophenols and heterocyclic oxidationbases, and the acid addition salts of the foregoing.
 10. The compositionaccording to claim 9 , wherein the para-phenylenediamines are chosenfrom the compounds of formula (V) below, and the addition salts thereofwith an acid:

in which: R₁₀ is chosen from a hydrogen atom, C₁-C₄ alkyl radicals,C₁-C₄ monohydroxyalkyl radicals, C₂-C₄ polyhydroxyalkyl radicals,(C₁-C₄)alkoxy(C₁-C₄)alkyl radicals, C₁-C₄ alkyl radicals substitutedwith at least one radical chosen from nitrogen-containing radicals,phenyl radicals and 4′-aminophenyl radicals; R₁₁ is chosen from ahydrogen atom, C₁-C₄ alkyl radicals, C₁-C₄ monohydroxyalkyl radicals,C₂-C₄ polyhydroxyalkyl radicals, (C₁-C₄)alkoxy(C₁-C₄)alkyl radicals andC₁-C₄ alkyl radicals substituted with at least one nitrogen-containingradical; R₁₂ is chosen from a hydrogen atom, halogen atoms, C₁-C₄ alkylradicals, C₁-C₄ monohydroxyalkyl radicals, C₁-C₄ hydroxyalkoxy radicals,acetylamino(C₁-C₄)alkoxy radicals, mesylamino(C₁-C₄)alkoxy radicals andcarbamoylamino(C₁-C₄)alkoxy radicals; R₁₃ is chosen from a hydrogenatom, halogen atoms and C₁-C₄ alkyl radicals.
 11. The compositionaccording to claim 10 , wherein said halides are chosen from chloride,bromides iodide, and fluoride.
 12. The composition according to claim 10, wherein said nitrogen-containing radicals are chosen from aminoradicals, mono(C₁-C₄)alkylamino radicals, di(C₁-C₄)alkylamino radicals,tri(C₁-C₄)alkylamino radicals, monohydroxy(C₁-C₄)alkylamino radicals,imidazolinium radicals and ammonium radicals.
 13. The compositionaccording to claim 9 , wherein the para-phenylenediamines are chosenfrom para-phenylenediamine, para-tolylenediamine,2-chloro-para-phenylenediamine, 2,3-dimethyl-para-phenylenediamine,2,6-dimethyl-para-phenylenediamine, 2,6-diethyl-para-phenylenediamine,2,5-dimethyl-para-phenylenediamine, N,N-dimethyl-para-phenylenediamine,N,N-diethyl-para-phenylenediamine, N,N-dipropyl-para-phenylenediamine,4-amino-N,N-diethyl-3-methylaniline,N,N-bis(-hydroxyethyl)-para-phenylenediamine,4-N,N-bis(-hydroxyethyl)amino-2-methylaniline,4-N,N-bis(-hydroxyethyl)amino-2-chloroaniline,2-hydroxyethyl-para-phenylenediamine, 2-fluoro-para-phenylenediamine,2-isopropyl-para-phenylenediamine,N-(-hydroxypropyl)-para-phenylenediamine,2-hydroxymethyl-para-phenylenediamine,N,N-dimethyl-3-methyl-para-phenylenediamine,N-ethyl-N-(-hydroxyethyl)-para-phenylenediamine,N-(-dihydroxypropyl)-para-phenylenediamine,N-(4′-aminophenyl)-para-phenylenediamine,N-phenyl-para-phenylenediamine, 2-hydroxyethyloxy-para-phenylenediamine,2-acetylaminoethyloxy-para-phenylenediamine andN-(-methoxyethyl)-para-phenylenediamine, and the addition salts thereofwith an acid.
 14. The composition according to claim 13 , wherein saidpara-phenylenediamines are chosen from para-phenylenediamine,para-tolylenediamine, 2-iso-propyl-para-phenylenediamine,2-β-hydroxyethyl-para-phenylenediamine,2-β-hydroxyethyloxy-para-phenylened iamine, 2,6-dimethyl-para-phenylenediamine, 2,6-diethyl-para-phenylenediamine,2,3-dimethyl-para-phenylenediamine,N,N-bis(β-hydroxyethyl)-para-phenylenediamine,2-chloro-para-phenylenediamine,2-β-acetylaminoethyloxy-para-phenylenediamine, and the acid additionsalts of any of the foregoing.
 15. The composition according to claim 9, wherein the double bases are chosen from the compounds correspondingto formula (VI) below, and the acid addition salts thereof:

wherein: B₁ and B₂, which may be identical or different, are each chosenfrom hydroxyl radicals and —NH₂ radicals, optionally substituted with atleast one radical chosen from C₁-C₄ alkyl radicals and linker arms Y;linker arm Y is chosen from linear and branched divalent alkylene chainscomprising from 1 to 14 carbon atoms, wherein said divalent alkylenechains may optionally be interrupted by at least one nitrogen-containingradical and optionally interrupted by at least one hetero atom such asan oxygen atom, a sulphur atom or a nitrogen atom, further wherein saiddivalent alkylene chains may optionally be terminated with at least onenitrogen-containing radical and optionally interrupted by at least oneheteroatom such as an oxygen atom, a sulphur atom or a nitrogen atom,and further wherein said divalent alkylene chains may optionally besubstituted with at least one radical chosen from hydroxyl radicals andC₁-C₆ alkoxy radicals; R₁₄ and R₁₅, which may be identical or different,are each chosen from a hydrogen atom, halogen atoms, C₁-C₄ alkylradicals, C₁-C₄ monohydroxyalkyl radicals, C₂-C₄ polyhydroxyalkylradicals, C₁-C₄ aminoalkyl radicals and linker arms Y; R₁₆, R₁₇, R₁₈,R₁₉, R₂₀ and R₂₁, which may be identical or different, are each chosenfrom a hydrogen atom, linker arms Y and C₁-C₄ alkyl radicals; with theproviso that only one linker arm Y is present in each compound offormula (VI).
 16. The composition according to claim 15 , wherein thedouble bases of formula (VI) are chosen fromN,N′-bis(β-hydroxyethyl)-N,N′-bis(4′-aminophenyl)-1,3-diaminopropanol,N,N′-bis(β-hydroxyethyl)-N,N′-bis(4′-aminophenyl)ethylenediamine,N,N′-bis(4-aminophenyl)tetramethylenediamine,N,N′-bis(p-hydroxyethyl)-N,N′-bis(4-aminophenyl)tetramethylenediamine,N,N′-bis(4-methylaminophenyl )tetramethylenediamine,N,N′-bis(ethyl)-N,N′-bis(4′-amino-3′-methylphenyl)ethylenediamine,1,8-bis(2,5-diaminophenoxy)-3,5-dioxaoctane, and the acid addition saltsof any of the foregoing.
 17. A composition according to claim 16 ,wherein said double bases are chosen fromN,N′-bis(β-hydroxyethyl)-N,N′-bis(4′-aminophenyl)-1,3-diaminopropanol,1,8-bis(2,5-diaminophenoxy)-3,5-dioxaoctane and the acid addition saltsof any of the foregoing.
 18. The composition according to claim 9 ,wherein the para-aminophenols are chosen from the compoundscorresponding to formula (VII) below, and the acid addition saltsthereof:

wherein: R₂₂ is chosen from a hydrogen atom, halogen atoms, C₁-C₄ alkylradicals, C₁-C₄ monohydroxyalkyl radicals, (C₁-C₄)alkoxy(C₁-C₄)alkylradicals, C₁-C₄ aminoalkyl radicals andhydroxy(C₁-C₄)alkylamino(C₁-C₄)alkyl radicals; and R₂₃ is chosen from ahydrogen atom, halogen atoms, C₁-C₄ alkyl radicals, C₁-C₄monohydroxyalkyl radicals, C₂-C₄ polyhydroxyalkyl radicals, C₁-C₄aminoalkyl radicals, cyano(C₁-C₄)alkyl radicals and(C₁-C₄)alkoxy(C₁-C₄)alkyl radicals, with the proviso that at least oneof R₂₂ and R₂₃ is a hydrogen atom.
 19. The composition according toclaim 18 , wherein the para-aminophenols are chosen frompara-aminophenol, 4-amino-3-methylphenol, 4-amino-3-fluorophenol,4-amino-3-hydroxymethylphenol, 4-amino-2-methyl phenol,4-amino-2-hydroxymethylphenol, 4-amino-2-methoxymethylphenol,4-amino-2-aminomethylphenol, 4-amino-2-(β-hydroxyethylaminomethyl)phenoland 4-amino-2-fluorophenol, and the acid addition salts of any of theforegoing.
 20. A composition according to claim 9 , wherein saidortho-aminophenols are chosen from 2-aminophenol,2-amino-5-methylphenol, 2-amino-6-methylphenol,5-acetamido-2-aminophenol and the acid addition salts of any of theforegoing.16. The composition according to claim 8 , wherein theheterocyclic bases are chosen from pyridine derivatives, pyrimidinederivatives and pyrazole derivatives, and the addition salts thereofwith an acid.
 21. The composition according to claim 1 , wherein the atleast one oxidation base is present in an amount generally ranging from0.0005% to 12% by weight relative to the total weight of the dyecomposition.
 22. The composition according to claim 1 , wherein saidcomposition contains at least one additional coupler and at least onedirect dye.
 23. The composition according to claim 22 , wherein the atleast one additional coupler is chosen from meta-phenylenediamines,meta-aminophenols, meta-diphenols and heterocyclic couplers.
 24. Thecomposition according to claim 22 , wherein the at least one additionalcoupler is present in an amount generally ranging from 0.0001% to 10%relative to the total weight of the dye composition.
 25. The compositionaccording to claim 1 , wherein the acid addition salts are chosen fromthe hydrochlorides, hydrobromides, sulphates, tartrates, lactates andacetates.
 26. The composition according to claim 1 , wherein saidcomposition is in the form of a liquid, a cream or a gel.
 27. Thecomposition according to claim 1 , wherein said linker arm D is chosenfrom linear and branched alkylene chains containing from 1 to 14 carbonatoms.
 28. A process for oxidation dyeing of keratin fibres comprising:applying to said keratin fibres for a sufficient time to develop adesired color at least one dye composition comprising, in a mediumsuitable for dyeing, (i) at least one oxidation base and (ii) at leastone coupler chosen from indolizine derivatives of formula (I) and theacid addition salts thereof:

wherein: n may be an integer from 0 to 4; R₁ and R₃, which may beidentical or different, are each chosen from hydrogen atoms; halogenatoms; Z groups; C₁-C₄ alkyl radicals; C₁-C₄ alkoxy radicals; C₁-C₄monohydroxyalkyl radicals; C₂-C₄ polyhydroxyalkyl radicals; C₁-C₄aminoalkyl radicals; acetylamino radicals; acetylamino-(C₁-C₄)alkylradicals; (C₁-C₄)alkoxy(C₁-C₄)alkyl radicals;mono(C₁-C₄)alkylamino(C₁-C₄)alkyl radicals;di(C₁-C₄)alkylamino(C₁-C₄)alkyl radicals; aminocarboxy(C₁-C₄)alkylradicals; acetyl(C₁-C₄)alkylamino(C₁-C₄)alkyl radicals; and aromaticrings which are optionally substituted with at least one radical chosenfrom halogen atoms, C₁-C₄ alkyl radicals, trifluoro-methyl radicals,C₁-C₄ alkoxy radicals, amino radicals, mono- and disubstituted aminoradicals wherein the substituent is chosen from C₁-C₄ alkyl radicals,(C₁-C₄)alkylamino(C₁-C₄)alkyl radicals, di(C₁-C₄)alkylamino(C₁-C₄)alkylradicals, carboxyl radicals and sulphoxy radicals; R₃ may optionallyfurther be chosen from 5- and 6-membered unsaturated heterocycles; R₂and R₄, which may be identical or different, are each chosen fromhydrogen atoms; halogen atoms, Z groups; C₁-C₄ alkyl radicals, C₁-C₄monohydroxyalkyl radicals, C₂-C₄ polyhydroxyalkyl radicals, C₁-C₄aminoalkyl radicals, mono(C₁-C₄)-alkylamino(C₁-C₄)alkyl radicals,di(C₁-C₄)alkyl-amino(C₁-C₄)alkyl radicals, carboxyl radicals, cyanoradicals, carboxy(C₁-C₄)alkyl radicals, nitro radicals and 5- and6-membered aromatic rings which are optionally substituted with at leastone radical chosen from halogen atoms, C₁-C₄ alkyl radicals,trifluoromethyl radicals, C₁-C₄ alkoxy radicals, amino radicals andmono- and disubstituted amino radicals wherein the substituent is chosenfrom C₁-C₄ alkyl radicals, (C₁-C₄)alkylamino-(C₁-C₄)alkyl radicals,di(C₁-C₄)alkylamino-(C₁-C₄)alkyl radicals, carboxyl radicals andsulphoxy radicals; Z is chosen from the following unsaturated cationicgroups of formulae (II) and (III) below, and the saturated cationicgroups of formula (IV) below:

in which: D is a linker arm which is chosen from linear and branchedalkylene chains which may be interrupted by at least one hetero atom,and which may be substituted with at least one substituent chosen fromhydroxyl and C₁-C₆ alkoxy radicals, and which may bear at least oneketone function; the ring members E, G, J, L and M, which may beidentical or different, are chosen from carbon, oxygen, sulphur andnitrogen atoms; b is an integer from 0 to 4; m is an integer from 0 to5; the radicals R, which may be identical or different, are chosen froma second group Z, which may be identical to or different from the firstgroup Z, halogen atoms, hydroxyl radicals, C₁-C₆ alkyl radicals, C₁-C₆monohydroxyalkyl radicals, C₂-C₆ polyhydroxyalkyl radicals, nitroradicals, cyano radicals, cyano(C₁-C₆)alkyl radicals, C₁-C₆ alkoxyradicals, tri(C₁-C₆)alkylsilane(C₁-C₆)alkyl radicals, amido radicals,aldehydo radicals, carboxyl radicals, (C₁-C₆)alkylcarbonyl radicals,thio radicals, C₁-C₆ thioalkyl radicals, C₁-C₆ alkylthio radicals, aminoradicals, amino radicals protected with at least one group chosen from(C₁-C₆)alkylcarbonyls, carbamyls and C₁-C₆ alkylsulphonyl radicals; NHR′and NR″R′″ groups in which R″ and R′″, which may be identical ordifferent, are chosen from C₁-C₆ alkyl radicals, C₁-C₆ monohydroxyalkylradicals and C₂-C₆ polyhydroxyalkyl radicals; R₅ is chosen from C₁-C₆alkyl radicals, C₁-C₆ mono-hydroxyalkyl radicals, C₂-C₆ polyhydroxyalkylradicals, cyano(C₁-C₆)alkyl radicals, tri(C₁-C₆)-alkylsilane(C₁-C₆)alkylradicals, (C₁-C₆)alkoxy-(C₁-C₆)alkyl radicals, carbamyl(C₁-C₆)alkylradicals, (C₁-C₆)alkylcarboxy(C₁-C₆)alkyl radicals, benzyl radicals andsecond Z groups which may be identical to or different from the first Zgroups; R₆, R₇ and R₈, which may be identical or different, are eachchosen from C₁-C₆ alkyl radicals, C₁-C₆ monohydroxyalkyl radicals, C₂-C₆polyhydroxyalkyl radicals, (C₁-C₆)alkoxy(C₁-C₆)alkyl radicals,cyano(C₁-C₆)alkyl radicals, aryl radicals, benzyl radicals,amido(C₁-C₆)alkyl radicals, tri(C₁-C₆)alkylsilane(C₁-C₆)alkyl radicalsand C₁-C₆ aminoalkyl radicals in which the amine is protected with atleast one group chosen from (C₁-C₆)alkylcarbonyls, carbamyls and C₁-C₆alkylsulphonyl radicals; two of the radicals R₆, R₇ and R₈, may alsoform, together with the nitrogen atom to which they are attached, 5- and6-membered saturated carbon-based rings and rings containing at leastone hetero atom, it being possible for the said ring to be optionallysubstituted with at least one substituent chosen from halogen atoms,hydroxyl radicals, C₁-C₆ alkyl radicals, C₁-C₆ monohydroxyalkylradicals, C₂-C₆ polyhydroxyalkyl radicals, nitro radicals, cyanoradicals, cyano(C₁-C₆)alkyl radicals, C₁-C₆ alkoxy radicals,tri(C₁-C₆)alkylsilane(C₁-C₆)alkyl radicals, amido radicals, aldehydoradicals, carboxyl radicals, keto(C₁-C₆)alkyl radicals, thio radicals,C₁-C₆ thioalkyl radicals, C₁-C₆ alkylthio radicals, amino radicals andamino radical protected with at least one group chosen from(C₁-C₆)alkylcarbonyls, carbamyls and C₁-C₆ alkylsulphonyl radicals; oneof the radicals R₆, R₇ and R₈ may optionally be chosen from second Zgroups, which may be identical to or different from the first Z groups;R₉ is chosen from C₁-C₆ alkyl radicals; C₁-C₆ monohydroxyalkyl radicals;C₂-C₆ polyhydroxyalkyl radicals; aryl radicals; benzyl radicals; C₁-C₆aminoalkyl radicals, C₁-C₆ aminoalkyl radicals wherein the amine isprotected by at least one group chosen from (C₁-C₆)alkylcarbonyls,carbamyls and C₁-C₆ alkylsulphonyl radicals; carboxy(C₁-C₆)alkylradicals; cyano(C₁-C₆)alkyl radicals; carbamyl(C₁-C₆)alkyl radicals;C₁-C₆ trifluoroalkyl radicals; tri(C₁-C₆)alkylsilane(C₁-C₆)alkylradicals; sulphonamido(C₁-C₆)alkyl radicals;(C₁-C₆)alkylcarboxy(C₁-C₆)alkyl radicals;(C₁-C₆)alkylsulphinyl(C₁-C₆)alkyl radicals;(C₁-C₆)alkylsulphonyl(C₁-C₆)alkyl radicals; (C₁-C₆)alkylketo(C₁-C₆)alkylradicals; N-(C₁-C₆)alkylcarbamyl(C₁-C₆)alkyl radicals; andN-(C₁-C₆)alkylsulphonamido(C₁-C₆)alkyl radicals; a and y are integersequal to 0 or 1; with the following provisos: in the unsaturatedcationic groups of formula (II): when a=0, the linker arm D is attachedto the nitrogen atom, when a=1, the linker arm D is attached to one ofthe ring members E, G, J and L, y cannot take the value 1 except: 1)when the ring members E, G, J and L simultaneously represent a carbonatom, and when the radical R₅ is attached to the nitrogen atom of theunsaturated ring; or alternatively 2) when at least one of the ringmembers E, G, J and L represents a nitrogen atom to which the radical R₅is attached; when b is at least 2, two adjacent radicals R may also formtogether a ring chosen from unsaturated 5- and 6-membered carbon-basedrings and rings containing at least one hetero atom; in the unsaturatedcationic groups of formula (III): when a=0, the linker arm D is attachedto the nitrogen atom, when a=1, the linker arm D is attached to one ofthe ring members E, G, J, L and M, y cannot take the value 1 except whenat least one of the ring members E, G, J, L and M represents a divalentatom, and when the radical R₅ is attached to the nitrogen atom of theunsaturated ring; when m is at least 2, two adjacent radicals R may alsoform together unsaturated 5- and 6-membered carbon-based rings and ringscontaining at least one hetero atom; in the cationic groups of formula(IV): when a=0, the linker arm D is attached to the nitrogen atombearing the radicals R₆ to R₈, when a =1, two of the radicals R₆ to R₈form, together with the nitrogen atom to which they are attached,saturated 5- and 6-membered rings as defined above, and the linker arm Dis attached to a carbon atom of the said saturated ring; X⁻ is chosenfrom monovalent and divalent anions; it being understood that: at leastone of the radicals R₁ and R₃ represents a hydrogen atom; and the numberof cationic groups Z is at least equal to
 1. 29. The compositionaccording to claim 28 , wherein said linker arm D is chosen from linearand branched alkylene chains containing from 1 to 14 carbon atoms. 30.The process according to claim 28 , wherein said keratin fibres arehuman hair.
 31. A process according to claim 28 , further comprisingapplying to said keratin fibres at least one oxidizing composition. 32.A process according to claim 28 , wherein said at least one dyecomposition further comprises at least one oxidizing agent.
 33. Aprocess according to claim 28 , wherein said desired color is developedat acidic, neutral or alkaline pH.
 34. A process according to claim 32 ,wherein said at least one oxidizing agent is added to said at least onedye composition at the time of application.
 35. A process according toclaim 31 , wherein said at least one oxidizing composition comprises atleast one oxidizing agent.
 36. A process according to claim 31 , whereinsaid at least one oxidizing composition is applied to said keratinfibres simultaneously with said at least one dye composition.
 37. Aprocess according to claim 31 , wherein said at least one oxidizingcomposition is applied to said keratin fibres sequentially with said atleast one composition.
 38. A process according to claim 31 , whereinsaid at least one oxidizing composition is mixed with said at least onedye composition prior to said applying.
 39. A process according to claim28 , wherein said keratin fibres are human keratin fibres.
 40. A processaccordingly to claim 39 , wherein said human keratin fibres are hair.41. A process according to claim 32 , wherein said at least oneoxidizing agent is chosen from hydrogen peroxide, urea peroxide, alkalimetal bromates, persalts, peracids and enzymes.
 42. A process accordingto claim 41 , wherein said persalts are chosen from perborates andpersulphates.
 43. A process according to claim 41 , wherein said enzymesare chosen from peroxidases, laccases, tyrosinases and oxidoreductases.44. A process according to claim 43 , wherein said oxidoreductases arechosen from pyranose oxidase, glucose oxidase, glycerol oxidase, lactateoxidase, pyruvate oxidase and uricase.
 45. A process according to claim35 , wherein said at least one oxidizing agent is chosen from hydrogenperoxide, urea peroxide, alkali metal bromates, persalts, peracids andenzymes.
 46. A process according to claim 45 , wherein said persalts arechosen from perborates and persulphates.
 47. A process according toclaim 46 , wherein said enzymes are chosen from peroxidases, laccases,tyrosinases and oxidoreductases.
 48. A process according to claim 47 ,wherein said oxidoreductases are chosen from pyranose oxidase, glucoseoxidase, glycerol oxidase, lactate oxidase, pyruvate oxidase anduricase.
 49. A process according to claim 28 , wherein said sufficienttime to develop a desired color ranges from 3 minutes to 56 minutes. 50.A process according to claim 49 , wherein said sufficient time todevelop a desired color ranges from 5 minutes to 30 minutes.
 51. Aprocess according to claim 28 , further comprising rinsing said keratinfibres.
 52. A process according to claim 51 , further comprising washingsaid keratin fibres with shampoo.
 53. A process according to claim 52 ,further comprising rinsing and drying said keratin fibres.
 54. A processaccording to claim 38 , wherein the pH of said at least one oxidizingcomposition mixed with said at least one dye composition ranges from 3to
 12. 55. A process according to claim 54 , wherein the pH of said atleast one oxidizing composition mixed with said at least one dyecomposition ranges from 5 to
 11. 56. A multicompartment device or kitfor oxidation dyeing of keratin fibres comprising a first compartmentcontaining a first composition comprising, in a medium suitable fordyeing, (i) at least one oxidation base and (ii) at least one couplerchosen from indolizine derivatives of formula (I) and the acid additionsalts thereof:

wherein: n may be an integer from 0 to 4; R₁ and R₃, which may beidentical or different, are each chosen from hydrogen atoms; halogenatoms; Z groups; C₁-C₄ alkyl radicals; C₁-C₄ alkoxy radicals; C₁-C₄monohydroxyalkyl radicals; C₂-C₄ polyhydroxyalkyl radicals; C₁-C₄aminoalkyl radicals; acetylamino radicals; acetylamino-(C₁-C₄)alkylradicals; (C₁-C₄)alkoxy(C₁-C₄)alkyl radicals;mono(C₁-C₄)alkylamino(C₁-C₄)alkyl radicals;di(C₁-C₄)alkylamino(C₁-C₄)alkyl radicals; aminocarboxy(C₁-C₄)alkylradicals; acetyl(C₁-C₄)alkylamino(C₁-C₄)alkyl radicals; and aromaticrings which are optionally substituted with at least one radical chosenfrom halogen atoms, C₁-C₄ alkyl radicals, trifluoro-methyl radicals,C₁-C₄ alkoxy radicals, amino radicals, mono- and disubstituted aminoradicals wherein the substituent is chosen from C₁-C₄ alkyl radicals,(C₁-C₄)alkylamino(C₁-C₄)alkyl radicals, di(C₁-C₄)alkylamino(C₁-C₄)alkylradicals, carboxyl radicals and sulphoxy radicals; R₃ may optionallyfurther be chosen from 5- and 6-membered unsaturated heterocycles; R₂and R₄, which may be identical or different, are each chosen fromhydrogen atoms; halogen atoms, Z groups; C₁-C₄ alkyl radicals, C₁-C₄monohydroxyalkyl radicals, C₂-C₄ polyhydroxyalkyl radicals, C₁-C₄aminoalkyl radicals, mono(C₁-C₄)-alkylamino(C₁-C₄)alkyl radicals,di(C₁-C₄)alkyl-amino(C₁-C₄)alkyl radicals, carboxyl radicals, cyanoradicals, carboxy(C₁-C₄)alkyl radicals, nitro radicals and 5- and6-membered aromatic rings which are optionally substituted with at leastone radical chosen from halogen atoms, C₁-C₄ alkyl radicals,trifluoromethyl radicals, C₁-C₄ alkoxy radicals, amino radicals andmono- and disubstituted amino radicals wherein the substituent is chosenfrom C₁-C₄ alkyl radicals, (C₁-C₄)alkylamino-(C₁-C₄)alkyl radicals,di(C₁-C₄)alkylamino-(C₁-C₄)alkyl radicals, carboxyl radicals andsulphoxy radicals; Z is chosen from the following unsaturated cationicgroups of formulae (II) and (III) below, and the saturated cationicgroups of formula (IV) below:

in which: D is a linker arm which is chosen from linear and branchedalkylene chains which may be interrupted by at least one hetero atom,and which may be substituted with at least one substituent chosen fromhydroxyl and C₁-C₆ alkoxy radicals, and which may bear at least oneketone function; the ring members E, G, J, L and M, which may beidentical or different, are chosen from carbon, oxygen, sulphur andnitrogen atoms; b is an integer from 0 to 4; m is an integer from 0 to5; the radicals R, which may be identical or different, are chosen froma second group Z, which may be identical to or different from the firstgroup Z, halogen atoms, hydroxyl radicals, C₁-C₆ alkyl radicals, C₁-C₆monohydroxyalkyl radicals, C₂-C₆ polyhydroxyalkyl radicals, nitroradicals, cyano radicals, cyano(C₁-C₆)alkyl radicals, C₁-C₆ alkoxyradicals, tri(C₁-C₆)alkylsilane(C₁-C₆)alkyl radicals, amido radicals,aldehydo radicals, carboxyl radicals, (C₁-C₆)alkylcarbonyl radicals,thio radicals, C₁-C₆ thioalkyl radicals, C₁-C₆ alkylthio radicals, aminoradicals, amino radicals protected with at least one group chosen from(C₁-C₆)alkylcarbonyls, carbamyls and C₁-C₆ alkylsulphonyl radicals; NHR″and NR″R′″ groups in which R″ and R′″, which may be identical ordifferent, are chosen from C₁-C₆ alkyl radicals, C₁-C₆ monohydroxyalkylradicals and C₂-C₆ polyhydroxyalkyl radicals; R₅ is chosen from C₁-C₆alkyl radicals, C₁-C₆ mono-hydroxyalkyl radicals, C₂-C₆ polyhydroxyalkylradicals, cyano(C₁-C₆)alkyl radicals, tri(C₁-C₆)-alkylsilane(C₁-C₆)alkylradicals, (C₁-C₆)alkoxy-(C₁-C₆)alkyl radicals, carbamyl(C₁-C₆)alkylradicals, (C₁-C₆)alkylcarboxy(C₁-C₆)alkyl radicals, benzyl radicals andsecond Z groups which may be identical to or different from the first Zgroups; R₆, R₇ and R₈, which may be identical or different, are eachchosen from C₁-C₆ alkyl radicals, C₁-C₆ monohydroxyalkyl radicals, C₂-C₆polyhydroxyalkyl radicals, (C₁-C₆)alkoxy(C₁-C₆)alkyl radicals,cyano(C₁-C₆)alkyl radicals, aryl radicals, benzyl radicals,amido(C₁-C₆)alkyl radicals, tri(C₁-C₆)alkylsilane(C₁-C₆)alkyl radicalsand C₁-C₆ aminoalkyl radicals in which the amine is protected with atleast one group chosen from (C₁-C₆)alkylcarbonyls, carbamyls and C₁-C₆alkylsulphonyl radicals; two of the radicals R₆, R₇ and R₈, may alsoform, together with the nitrogen atom to which they are attached, 5- and6-membered saturated carbon-based rings and rings containing at leastone hetero atom, it being possible for the said ring to be optionallysubstituted with at least one substituent chosen from halogen atoms,hydroxyl radicals, C₁-C₆ alkyl radicals, C₁-C₆ monohydroxyalkylradicals, C₂-C₆ polyhydroxyalkyl radicals, nitro radicals, cyanoradicals, cyano(C₁-C₆)alkyl radicals, C₁-C₆ alkoxy radicals,tri(C₁-C₆)alkylsilane(C₁-C₆)alkyl radicals, amido radicals, aldehydoradicals, carboxyl radicals, keto(C₁-C₆)alkyl radicals, thio radicals,C₁-C₆ thioalkyl radicals, C₁-C₆ alkylthio radicals, amino radicals andamino radical protected with at least one group chosen from(C₁-C₆)alkylcarbonyls, carbamyls and C₁-C₆ alkylsulphonyl radicals; oneof the radicals R₆, R₇ and R₈ may optionally be chosen from second Zgroups, which may be identical to or different from the first Z groups;R₉ is chosen from C₁-C₆ alkyl radicals; C₁-C₆ monohydroxyalkyl radicals;C₂-C₆ polyhydroxyalkyl radicals; aryl radicals; benzyl radicals; C₁-C₆aminoalkyl radicals, C₁-C₆ aminoalkyl radicals wherein the amine isprotected by at least one group chosen from (C₁-C₆)alkylcarbonyls,carbamyls and C₁-C₆ alkylsulphonyl radicals; carboxy(C₁-C₆)alkylradicals; cyano(C₁-C₆)alkyl radicals; carbamyl(C₁-C₆)alkyl radicals;C₁-C₆ trifluoroalkyl radicals; tri(C₁-C₆)alkylsilane(C₁-C₆)alkylradicals; sulphonamido(C₁-C₆)alkyl radicals;(C₁-C₆)alkylcarboxy(C₁-C₆)alkyl radicals;(C₁-C₆)alkylsulphinyl(C₁-C₆)alkyl radicals;(C₁-C₆)alkylsulphonyl(C₁-C₆)alkyl radicals; (C₁-C₆)alkylketo(C₁-C₆)alkylradicals; N-(C₁-C₆)alkylcarbamyl(C₁-C₆)alkyl radicals; andN-(C₁-C₆)alkylsulphonamido(C₁-C₆)alkyl radicals; a and y are integersequal to 0 or 1; with the following provisos: in the unsaturatedcationic groups of formula (II): when a=0, the linker arm D is attachedto the nitrogen atom, when a=1, the linker arm D is attached to one ofthe ring members E, G, J and L, y cannot take the value 1 except: 1)when the ring members E, G, J and L simultaneously represent a carbonatom, and when the radical R₅ is attached to the nitrogen atom of theunsaturated ring; or alternatively 2) when at least one of the ringmembers E, G, J and L represents a nitrogen atom to which the radical R₅is attached; when b is at least 2, two adjacent radicals R may also formtogether a ring chosen from unsaturated 5- and 6-membered carbon-basedrings and rings containing at least one hetero atom; in the unsaturatedcationic groups of formula (III): when a=0, the linker arm D is attachedto the nitrogen atom, when a=1, the linker arm D is attached to one ofthe ring members E, G, J, L and M, y cannot take the value 1 except whenat least one of the ring members E, G, J, L and M represents a divalentatom, and when the radical R₅ is attached to the nitrogen atom of theunsaturated ring; when m is at least 2, two adjacent radicals R may alsoform together unsaturated 5- and 6-membered carbon-based rings and ringscontaining at least one hetero atom; in the cationic groups of formula(IV): when a=0, the linker arm D is attached to the nitrogen atombearing the radicals R₆ to R₈, when a=1, two of the radicals R₆ to R₈form, together with the nitrogen atom to which they are attached,saturated 5- and 6-membered rings as defined above, and the linker arm Dis attached to a carbon atom of the said saturated ring; X⁻ is chosenfrom monovalent and divalent anions; it being understood that: at leastone of the radicals R₁ and R₃ represents a hydrogen atom; and the numberof cationic groups Z is at least equal to 1; and a second compartmentcontaining at least one oxidizing composition.
 57. The compositionaccording to claim 56 , wherein said linker arm D is chosen from linearand branched alkylene chains containing from 1 to 14 carbon atoms.
 58. Acompound chosen from indolizine derivatives of formula (I), and acidaddition salts thereof,

wherein: n may be an integer from 0 to 4; R₁ and R₃, which may beidentical or different, are each chosen from hydrogen atoms; halogenatoms; Z groups; C₁-C₄ alkyl radicals; C₁-C₄ alkoxy radicals; C₁-C₄monohydroxyalkyl radicals; C₂-C₄ polyhydroxyalkyl radicals; C₁-C₄aminoalkyl radicals; acetylamino radicals; acetylamino-(C₁-C₄)alkylradicals; (C₁-C₄)alkoxy(C₁-C₄)alkyl radicals;mono(C₁-C₄)alkylamino(C₁-C₄)alkyl radicals;di(C₁-C₄)alkylamino(C₁-C₄)alkyl radicals; aminocarboxy(C₁-C₄)alkylradicals; acetyl(C₁-C₄)alkylamino(C₁-C₄)alkyl radicals; and aromaticrings which are optionally substituted with at least one radical chosenfrom halogen atoms, C₁-C₄ alkyl radicals, trifluoro-methyl radicals,C₁-C₄ alkoxy radicals, amino radicals, mono- and disubstituted aminoradicals wherein the substituent is chosen from C₁-C₄ alkyl radicals,(C₁-C₄)alkylamino(C₁-C₄)alkyl radicals, di(C₁-C₄)alkylamino(C₁-C₄)alkylradicals, carboxyl radicals and sulphoxy radicals; R₃ may optionallyfurther be chosen from 5- and 6-membered unsaturated heterocycles; R₂and R₄, which may be identical or different, are each chosen fromhydrogen atoms; halogen atoms, Z groups; C₁-C₄ alkyl radicals, C₁-C₄monohydroxyalkyl radicals, C₂-C₄ polyhydroxyalkyl radicals, C₁-C₄aminoalkyl radicals, mono(C₁-C₄)-alkylamino(C₁-C₄)alkyl radicals,di(C₁-C₄)alkyl-amino(C₁-C₄)alkyl radicals, carboxyl radicals, cyanoradicals, carboxy(C₁-C₄)alkyl radicals, nitro radicals and 5- and6-membered aromatic rings which are optionally substituted with at leastone radical chosen from halogen atoms, C₁-C₄ alkyl radicals,trifluoromethyl radicals, C₁-C₄ alkoxy radicals, amino radicals andmono- and disubstituted amino radicals wherein the substituent is chosenfrom C₁-C₄ alkyl radicals, (C₁-C₄)alkylamino-(C₁-C₄)alkyl radicals,di(C₁-C₄)alkylamino-(C₁-C₄)alkyl radicals, carboxyl radicals andsulphoxy radicals; Z is chosen from the following unsaturated cationicgroups of formulae (II) and (III) below, and the saturated cationicgroups of formula (IV) below:

in which: D is a linker arm which is chosen from linear and branchedalkylene chains which may be interrupted by at least one hetero atom,and which may be substituted with at least one substituent chosen fromhydroxyl and C₁-C₆ alkoxy radicals, and which may bear at least oneketone function; the ring members E, G, J, L and M, which may beidentical or different, are chosen from carbon, oxygen, sulphur andnitrogen atoms; b is an integer from 0 to 4; m is an integer from 0 to5; the radicals R, which may be identical or different, are chosen froma second group Z, which may be identical to or different from the firstgroup Z, halogen atoms, hydroxyl radicals, C₁-C₆ alkyl radicals, C₁-C₆monohydroxyalkyl radicals, C₂-C₆ polyhydroxyalkyl radicals, nitroradicals, cyano radicals, cyano(C₁-C₆)alkyl radicals, C₁-C₆ alkoxyradicals, tri(C₁-C₆)alkylsilane(C₁-C₆)alkyl radicals, amido radicals,aldehydo radicals, carboxyl radicals, (C₁-C₆)alkylcarbonyl radicals,thio radicals, C₁-C₆ thioalkyl radicals, C₁-C₆ alkylthio radicals, aminoradicals, amino radicals protected with at least one group chosen from(C₁-C₆)alkylcarbonyls, carbamyls and C₁-C₆ alkylsulphonyl radicals; NHR″and NR″R′″ groups in which R″ and R′″, which may be identical ordifferent, are chosen from C₁-C₆ alkyl radicals, C₁-C₆ monohydroxyalkylradicals and C₂-C₆ polyhydroxyalkyl radicals; R₅ is chosen from C₁-C₆alkyl radicals, C₁-C₆ mono-hydroxyalkyl radicals, C₂-C₆ polyhydroxyalkylradicals, cyano(C₁-C₆)alkyl radicals, tri(C₁-C₆)-alkylsilane(C₁-C₆)alkylradicals, (C₁-C₆)alkoxy-(C₁-C₆)alkyl radicals, carbamyl(C₁-C₆)alkylradicals, (C₁-C₆)alkylcarboxy(C₁-C₆)alkyl radicals, benzyl radicals andsecond Z groups which may be identical to or different from the first Zgroups; R₆, R₇ and R₈, which may be identical or different, are eachchosen from C₁-C₆ alkyl radicals, C₁-C₆ monohydroxyalkyl radicals, C₂-C₆polyhydroxyalkyl radicals, (C₁-C₆)alkoxy(C₁-C₆)alkyl radicals,cyano(C₁-C₆)alkyl radicals, aryl radicals, benzyl radicals,amido(C₁-C₆)alkyl radicals, tri(C₁-C₆)alkylsilane(C₁-C₆)alkyl radicalsand C₁-C₆ aminoalkyl radicals in which the amine is protected with atleast one group chosen from (C₁-C₆)alkylcarbonyls, carbamyls and C₁-C₆alkylsulphonyl radicals; two of the radicals R₆, R₇ and R₈, may alsoform, together with the nitrogen atom to which they are attached, 5- and6-membered saturated carbon-based rings and rings containing at leastone hetero atom, it being possible for the said ring to be optionallysubstituted with at least one substituent chosen from halogen atoms,hydroxyl radicals, C₁-C₆ alkyl radicals, C₁-C₆ monohydroxyalkylradicals, C₂-C₆ polyhydroxyalkyl radicals, nitro radicals, cyanoradicals, cyano(C₁-C₆)alkyl radicals, C₁-C₆ alkoxy radicals,tri(C₁-C₆)alkylsilane(C₁-C₆)alkyl radicals, amido radicals, aldehydoradicals, carboxyl radicals, keto(C₁-C₆)alkyl radicals, thio radicals,C₁-C₆ thioalkyl radicals, C₁-C₆ alkylthio radicals, amino radicals andamino radical protected with at least one group chosen from(C₁-C₆)alkylcarbonyls, carbamyls and C₁-C₆ alkylsulphonyl radicals; oneof the radicals R₆, R₇ and R₈ may optionally be chosen from second Zgroups, which may be identical to or different from the first Z groups;R₉ is chosen from C₁-C₆ alkyl radicals; C₁-C₆ monohydroxyalkyl radicals;C₂-C₆ polyhydroxyalkyl radicals; aryl radicals; benzyl radicals; C₁-C₆aminoalkyl radicals, C₁-C₆ aminoalkyl radicals wherein the amine isprotected by at least one group chosen from (C₁-C₆)alkylcarbonyls,carbamyls and C₁-C₆ alkylsulphonyl radicals; carboxy(C₁-C₆)alkylradicals; cyano(C₁-C₆)alkyl radicals; carbamyl(C₁-C₆)alkyl radicals;C₁-C₆ trifluoroalkyl radicals; tri(C₁-C₆)alkylsilane(C₁-C₆)alkylradicals; sulphonamido(C₁-C₆)alkyl radicals;(C₁-C₆)alkylcarboxy(C₁-C₆)alkyl radicals;(C₁-C₆)alkylsulphinyl(C₁-C₆)alkyl radicals;(C₁-C₆)alkylsulphonyl(C₁-C₆)alkyl radicals; (C₁-C₆)alkylketo(C₁-C₆)alkylradicals; N-(C₁-C₆)alkylcarbamyl(C₁-C₆)alkyl radicals; andN-(C₁-C₆)alkylsulphonamido(C₁-C₆)alkyl radicals; a and y are integersequal to 0 or 1; with the following provisos: in the unsaturatedcationic groups of formula (II): when a=0, the linker arm D is attachedto the nitrogen atom, when a=1, the linker arm D is attached to one ofthe ring members E, G, J and L, y cannot take the value 1 except: 1)when the ring members E, G, J and L simultaneously represent a carbonatom, and when the radical R₅ is attached to the nitrogen atom of theunsaturated ring; or alternatively 2) when at least one of the ringmembers E, G, J and L represents a nitrogen atom to which the radical R₅is attached; when b is at least 2, two adjacent radicals R may also formtogether a ring chosen from unsaturated 5- and 6-membered carbon-basedrings and rings containing at least one hetero atom; in the unsaturatedcationic groups of formula (III): when a=0, the linker arm D is attachedto the nitrogen atom, when a=1, the linker arm D is attached to one ofthe ring members E, G, J, L and M, y cannot take the value 1 except whenat least one of the ring members E, G, J, L and M represents a divalentatom, and when the radical R₅ is attached to the nitrogen atom of theunsaturated ring; when m is at least 2, two adjacent radicals R may alsoform together unsaturated 5- and 6-membered carbon-based rings and ringscontaining at least one hetero atom; in the cationic groups of formula(IV): when a=0, the linker arm D is attached to the nitrogen atombearing the radicals R₆ to R₈, when a=1, two of the radicals R₆ to R₈form, together with the nitrogen atom to which they are attached,saturated 5- and 6-membered rings as defined above, and the linker arm Dis attached to a carbon atom of the said saturated ring; X⁻ is chosenfrom monovalent and divalent anions; with the following provisos: atleast one of the radicals R₁ and R₃ represents a hydrogen atom; and thenumber of cationic groups Z is at least equal to 1; Z cannot be chosenfrom the cationic groups of formula (IV); and4-methyl-4-[2-(2-phenyl-1-indolizinyl)ethyl]morpholinium bromide isexcluded.
 59. The composition according to claim 58 , wherein saidlinker arm D is chosen from linear and branched alkylene chainscontaining from 1 to 14 carbon atoms.
 60. The compound according toclaim 58 , wherein said compound is chosen from:1-methyl-2-[2-(7-methyl-2-phenylindolizin-3-yl)ethyl]pyridinium methylsulphate;3-methyl-1-[2-(7-methyl-2-phenylindolizin-3-yl)-2-oxoethyl]-3H-imidazol-1-iumchloride;3-methyl-1-[2-(2-methylindolizin-3-yl)-2-oxoethyl]-3H-imidazol-1-iumchloride;1-{2-[2-(4-methoxyphenyl)-8-methylindolizin-3-yl]-2-oxoethyl}-3-methyl-3H-imidazol-1-iumchloride;3-methyl-1-{2-[8-methyl-2-(3-nitrophenyl)indolizin-3-yl]-2-oxoethyl}-3H-imidazol-1-ium chloride;1-{2-[2-(3-nitrophenyl)indolizin-3-yl]-2-oxoethyl}pyridinium chloride;1-[2-oxo-2-(2-phenylindolizin-3-yl)ethyl]pyridinium chloride;1-[2-oxo-2-(2-m-tolylindolizin-3-yl)ethyl]pyridinium chloride;1-[2-(8,1-{2-[2-(4-methoxyphenyl)-8-methylindolizin-3-yl]-2-oxoethyl}-2-methylpyridiniumchloride; 2-phenylindolizin-3-yl)-2-oxoethyl]pyridinium methyl chloride;[2-(8-methyl-2-phenylindolizin-3-yl)-2-oxoethyl] pyridinium chloride;2-methyl-1-{2-[2-(3-nitrophenyl)indolizin-3-yl]-2-oxoethyl}pyridiniumchloride; 2-methyl-1-[2-oxo-2-(2-phenylindolizin-3-yl)ethyl]pyridiniumchloride;2-methyl-1-{2-[8-methyl-2-(3-nitrophenyl)indolizin-3-yl]-2-oxoethyl}pyridin ium chloride;2-methyl-1-[2-(8-methyl-2-phenylindolizin-3-yl)-2-oxoethyl]pyridiniumchloride;3-methoxycarbonyl-1-{2-[2-(3-nitrophenyl)indolizin-3-yl]-2-oxoethyl}pyridiniumchloride;3-methoxycarbonyl-1-[2-oxo-2-(2-phenylindolizin-3-yl)ethyl]pyridiniumchloride;3-methoxycarbonyl-1-{2-[2-(4-methoxyphenyl)-8-methylindolizin-3-yl]-2-oxoethyl}pyridiniumchloride;3-methoxycarbonyl-1-{2-[8-methyl-2-(3-nitrophenyl)indolizin-3-yl]-2-oxoethyl}pyridin ium chloride;3-methoxycarbonyl-1-[2-(8-methyl-2-phenylindolizin-3-yl)-2-oxoethyl]pyridiniumchloride; and the addition salts thereof with an acid.